Fast, Cheap and Out of Control

Ah shoot

2012-01-16T13:55:00.002-06:00

Despite being an engineer and having quite a bit of experience with computer type things, writing code, configuring networks, hardware, software... etc. I find myself being completely unable to navigate simple systems. Facebook boggles the hell out of me, "i" phones dont make any damn sense at all, and apparently the totally idiot-proof interface of 'blogger' is beyond my technical sophistication.

Long story short, I started out trying to figure out why the heading photo got resized down to tiny, and somehow i messed up my blog. Now pictures are all whack-sized, colors and themes are lost, and a bunch of time i put into making it somewhat readable over the years is all gone. It took me a couple weeks just to figure out how the heck to get back 'in' to the control interface and make it somewhat legible.

If i get some time here in the next couple weeks i'll try to fix things and add some of the new fun things i've been working on. In the meantime sorry if it looks crazy around here.

I'm putting some time into developing a new website for moped factory, and parent company motzing engineered components, on my own server, without glitzy templates and crap... just something simple and ugly (think geocities style) with good valuable content, then i can keep this blog for updates on dumb stuff like when i changed a throttle cable and when i'm feeling sad about backstreet boys not getting back together, and whatever else dumb stuff that people put on these things... cake photos?

A quick one

2011-12-11T19:12:00.004-06:00

Not much to say, trying to blarg at you more often than not here, but its not easy with everything else going on. Plus things in my own garage are pretty stagnant at the moment, haven't made much progress on any of my poorly running bikes.

Despite my best effort however (to avoid buying more bikes), I did acquire another $100 Pinto. I know you guys on the coasts (or anywhere that isn't milwaukee, i guess) will hate me for this, but its almost hard not to buy $100 barn-fresh Pintos here. This would probably be the 7, 8, maybe 9th Pinto that has come to me in about this same condition.

From Blk Pinto 12_11

The throttle cable is ALWAYS broken, the chain is usually froze up (missing in this case), the forks are loose as hell, and the pedals are bent, but the EE-FIDDY is in great shape. No speedo, so no clue what the miles are, but the tires are original and hold air. Not too worn down either.

From Blk Pinto 12_11

It also came with 2 14mm bing carbs and a box of other fail from the previous owner trying to resurrect it. I talked to him and he wants to buy it back from me if I get it running, but the more I think about it, the more hoarder-ey I feel. I've never had one of these with snowflakes before, I usually get the 'red' orange ones with spokes. I dont really like snowflakes but for some reason I really like this little bike. Either way it will have to wait a couple weeks for me to get my dollars up enough to sort it out properly.

Speaking of getting my dollars up (a phrase borrowed from The Illustrious Miles Fox) I've been cranking out new parts like a monkey on crack lately.

I turned a few heads for the Treats gang, the bulk of it Puch stuff, but also trying to bulk up supplies of vespa, motobecane, and there might be a debris laying around somewhere. The Metrakit 65 head I started doing 5 or so years ago is still a hot seller, and my processes (sandblasting, paint, finishing) have gotten a lot better thanks to my new machine shop and upgraded tooling. I daresay these are some of the nicest heads I've ever made.

I also finally put a bracket that has been riding around on the bottom of my sachs since, oh, 2007? into production. The final version is burly 12 ga steel and powdered in MopedFactory blue. It will let you put a Simonini Peugeot Circuit pipe on your lowly Sachs 505. Anybody want to test it on a 504? Freebeeez! The way the pipe is set up from the factory, the header is the exact same size as the nipple of the Athena Kit, but for stockers, you'll need a little shim. I'll be making those very soon so hang on to your hat.

From Sachs simo exhaust bracket

Oh yeah, what else you ask? As if all those fantastic parts that i've been slaving over isn't enough to make you happy, I went ahead and did another production run of ZA-50 Billet oil fill plugs. Why? Because I needed a couple for myself and figured while I was at it, might as well make 20 or so.

From za 50 drain plug

These new ones are, once again, better because of the improved equipment at the new shop. There is a miracle machine there called a 'speed lathe' that makes it easy for me to keep the quality control on these like 300% more consistent. The last batch I ended up throwing out about 1 in 5 due to the o-ring groove getting cut funky, but this batch came out almost perfect. They also are faster to make, but I cant drop the price people, geez they are already cheaper than the 30 year old rubber crap Puch is trying to give you... and it ain't even in stock.

oh yeah these fit in your rare as hell x-50 3 speed hand shift moped engine also, but dont bring it up, i just sold mine and it makes me a very sad panda. Oh well, on to bigger and faster things hopefully.

A shop day, back on the Pugeot

2011-12-01T11:00:00.000-06:00

I was able to get a day in my workshop finally after several weeks. When I started making mopeds my business, I had plenty of moped time to go around and was able to keep up on a running bike or two, my projects, etc. Now that life has gotten crazier all moped time (which is much less) goes into making parts now, and a pure, unadulterated, shop day of just dicking around and sorting things out, is a rare joy.

I cant remember where I started, but first project was Le Peugeot. This was easy stuff but frustrating/time consuming BS. When I loaned it out at the rally, somehow (this was probably happening before the rally but I didn't notice) the exhaust rapidly began disintegrating into its component parts. This is that stupid pipe that started life as a 'faco' and is now mostly hand fabricated with only a section of the chamber original.

From Puegeot

The flange that screws into the cylinder broke off, so i welded in the higher-quality stock peugeot flange and a section of pipe, along with the peugeot stock nut which was much nicer. This held for most of the summer, but finally let go sometime during the rally. My apologies to Seth for the bum-ass loaner bike. The wimpy little sheet metal bracket under the engine disintegrated even after being welded closed, and it didn't take long for the flange/header to break and let go.

So yeah, i welded that back together. The handlebars that I started replacing a couple weeks ago finally got new longer cables that aren't frayed and corroded, and now the handlebars aren't bent and hastily welded back together. Also a much more comfortable angle.

From Puegeot

True to form, she fired up on the second kick after i dumped a carb-bowl full of varnish gas out. My bone head brother stole my good fat OEM peugeot belt and i was forced to use his rolled-over shredded to heck belt of unknown provenance. The bike was a totally new animal with the thinner belt, definitely helped even though it was slipping like crazy.

From Puegeot

Rode to work yesterday and made it, although i still cant figure out this top end 4-stroking/misfire thing. I've tried different timing, different jetting, different plugs, and i'm still totally flummoxed. It just feels gutless, like bad timing, on the top end, then when you go down a hill or pick up speed around 37-38 mph it starts to four-stroke like crazy and slow down.

The intake is still stock and who knows what is going on with that pipe, so either of those could be causing the flow to choke abruptly. In the next couple weeks when i get paid for a few things (most notably selling my precious X-50 motor) i'll invest in one of those malossi SHA intakes and put the 16 SHA that came off my 'ella' maxi on to the Peugeot and see if we cant get her blasting properly. Also the variator still needs attending to, so that will probably happen all at once.

Two steps forward, four steps back

2011-11-11T20:00:00.000-06:00

I'm not quite ready to go Mike Ness on the whitehouse or anything, but these lousy A35 manifolds were a bit of a set back. In addition to taking way too much effort to make and costing me a ton to set up all the jigs and such, they have been somewhat problematic in that they are the first product I've made like this. There is a good reason nobody else makes these things!

Version 1

From Moped Factory Products

The first batch of 10 had some quality control issues first of all, the welds left something to be desired visually (they were airtight- tig welded inside) and the powdercoating was a bit spotty. Definitely not up to Moped Factory standards. I was in too much of a rush and sent them out anyway and right away one of my product crash testers got back to me and said that there was a placement error, on the A35 frame the old intake (ver 2) went right into the front side cover bracket. The bike I tested them on was an A3 and slightly different in that area.

Version 2

From Moped Factory Products

So last weekend, the forward progress was interrupted to re-make the offending manifolds, with what I hope will be a more universal and all-around better design. Version 3 of the manifold is less trick, bringing the carb out farther from the frame, and on the right side this time (starboard), instead of the port side. As much as I like designs that allow you to keep things tucked in neatly, the Tomos engine and frame layout doesn't give much of an option for that. Perhaps in version 4 I'll use an actual a35 frame and make it specific to that model, in the mean time I've got something that will get the job done and should be a bit more universal for all the hackers and wierdos out there putting these things on Puchs, Batavus (more regarding this soon!), etc.

Version 3

From Moped Factory Products

The new models are welded with some tricky machine shop magic to give much better looking welds. Mig, not tig, which has certain advantages to the manufacturing process. Mostly that its faster and doesn't heat up the plate as much, so it wont warp as badly, and it looks so nice.

From Moped Factory Products

And another pic to show clearance:

From Moped Factory Products

This is finals week coming up here, so I'm working on a pile of final reports and crap, but next week I'll be hard at it getting some more exciting new products out and I'll mock up a puch frame to make sure this intake clears... take some pictures.

If all goes well, hopefully I can get some work done on some of my own projects, might make for more interesting blogging.

Ho-lee-crap

2011-11-04T10:02:00.002-05:00

All I can say is ... wow. If you have even the slightest bit of gasoline in your veins, these youtube videos are stunning to see.

Moar parts

2011-11-01T11:56:00.004-05:00

Had a busy weekend, finally was able to finish up a couple products I've been developing during the last few weeks.

From Moped Factory Products

It sounds kinda silly saying that, because most of you (especially if you had a machine shop at hand) could have made any of these things in a couple hours, but its totally different when you are producing things to sell. Testing, quality control, all kinds of things have to be done. A big part of what this experiment with the moped business is teaching me is the concept of 'design for manufacturability'. It means altering your design to make a product easier to produce, or more consistent to mass produce. Its the missing link often between a good product and a great product, or making a profit/not making a profit.

If you're going to stake your reputation on a product, you better be darn sure its going out the door correctly made, a big part of that is consistency. When you make one intake you can mock it up on your bike, tack it in place, bend it to fit, finish weld... when you make 10 intakes you have to make a jig to cut the tube, a jig to bend the tube, a jig to hold it while you weld. By the time you're done with all that you've spent weeks engineering a process. The good news is, it pays off in time by ensuring a high quality product and making them cheaper to mass produce. Oh yeah, I'm learning a lot as well, and as my mom always says 'education is expensive'.

The first part i'm excited about i've been making for awhile, just for my own use and for friends. These 'E50' stands- which fit all puch engines, of course- are really handy for rebuilds and for starting your engine on the bench. The originals had goobery welds on the outside, and weren't always 100% perfectly square. I made some changes to my design and managed to hide the welds, make them stronger and more accurate, and shoot some pretty blue powder on them.

From Moped Factory Products

What do you think? The blue powder was a reccommendation of my brother who is always reminding me I should work harder at getting radical. Black would have been the safe choice, but I like this blue, and now when you start seeing all my stuff coming out in blue, maybe you'll recognize moped factory products when you see them on other people's cool mopeds, or something... I'm retarded when it comes to marketing, so y'all should know that MF stuff is less than 2% hype. Boring eh? Whatever, if you want hype go buy some Coke or a pair of Nikes.

The other part that i've put a ton of time into lately... and boy have i ever... is this A35 to 16SHA intake manifold. Ever since Handybikes ran out of Daelim manifolds sometime around 2008, there has been a lot of hair-pulling by the moped community about finding a good, well fitting, 16mm SHA manifold to fit the A35. You can use that straight shot one from treats, maybe, if you have just the right carb and the gods are smiling upon you. And dont even think about changing a jet or running an air filter.

From Moped Factory Products

A guy emailed me asking if I could make him one and it got my juices flowing about this part again. I'm literally going to bleed money on these things, but they are so cool and so badly needed, consider it community service or something. It required about 10 modifications to my plasma-cut flange, to get just the right angle on the pass-through of the tube. A jig had to be made to ensure the bender would bend the tube at just the right angle, a jig was made to hold the tube and cut it at just the right angle, and the tube itself requires a machining step to put the clamp-mount spigot on the end just perfect.

After about 10 prototypes moving the carb into different locations, it ended up here. I mocked it up on an A3 so hopefully it works on A35 frames just the same. I cant exactly remember how those frames are different (if at all) but it should clear side covers and everything, so you can keep sleeper status even with a kit.

This week I'm cleaning up the garage and getting ready to put together my ZA-50 finally. This stupid thing has taken me forever, basically because I want it to be perfect and run forever. Is that too much to ask? The last ZA-50 I rebuilt had at least 20k on it before the bearings got so sloppy that I finally had to retire it. Hopefully this one with improvements like relined clutches, roller bearing crank, and higher quality bearings (I've replaced almost every single bearing in the whole engine) will allow it to run hard with a Polini for many years to come as a daily blaster.

central standard daylight savings time

2011-10-26T13:15:00.003-05:00

It has been a crazy summer, too crazy to 'blog' about in fact.

My lovely girlfriend and I had a kid:

From Blogg

My brother moved in with us to go to school for industrial design

From cranks rally 11

I partied in Chicago
(photo redacted)

I made some moped parts

From Moped Factory Products

And I worked on a few projects

From Bridgestone

New Bridgestone 100GP

From Sea-Bee outboard

1948 'Sea-Bee' by Gale outboard, totally rebuilt and restored

plus lots more!

I'll try to start writing up some of my summer projects here and there when i have time. The outboard just got finished yesterday, so if the glue is all dry i'll probably start it up tonight and post up that restoration process soon.

The red sachs 'sally' has also come a long way, but it really makes me depressed with the constant not-running-ness, and now its leaking out all its trans oil, so that one might be awhile.

There is a really nice Polini ZA50 in my garage also on the cusp of going back together with lots of custom goodies. I'll be taking pictures of that as it goes together and posting it up as well.

Most of my moped time has been going into Moped Factory lately, building the product base and expanding our offerings, plus keeping up with demand. More good stuff on that front is coming also.

Peugeot, finally

2011-05-11T10:29:00.000-05:00

If you're a compulsive moped tinkerer such as myself (and why would you be reading this blog if you aren't one?) you probably have had periods in your life where you were forced to daily-drive a bike that just isn't right. For me that period was this entire winter. I rely on my bikes for 365-days-a-year transport to school and work, so its pretty frustrating when my daily driver isn't sorted out, and having my workshop way the heck on the north side, without a station wagon or truck to move mopeds in, this winter has been very frustrating indeed. The poor little Pug has spent most of the winter maligned, and limping along way out-of-tune.

Since this little green 103 is my first foray into Peugeot tuning, there have been some speed bumps this winter getting the old girl running just right. Since it is an ongoing project, and pretty much the only thing i'm doing that I can talk about, I've been whining on here about the trials and tribulations encountered while setting it up.

So, it is after a ton of mucking around that I am so happy to report that this bike is finally sorted out and will be receiving a 'cranks' headlight sticker, as it is finally worthy.

About 2 weeks ago, I forced open a hole in my schedule and stopped by Blaze's garage, which is about 1/3 the distance to my workshop, and he has the Pug puller set. I was concerned that the last time i put the flywheel on, i clocked it in the wrong position. I removed the flywheel and reinstalled it, started up the bike, and was very confused by the fact that the pedals were spinning vigorously. D'oh! Put the damn flywheel on backwards, so the engine was running in reverse. Pulled it off again and re-installed it to find that the timing marks i had on there from the first time, and i had lined up to the second time, were still dead-on.

I set the timing at 1.40 mm as accurately as possible, and took off. By the time i got home, i was seeing the same heat fade, loss of torque, etc. as i was before re-clocking the flywheel.

About a week ago I finally got the Peugeot head machining Jig finished and turned an extra stock head I had laying around. I swapped that on later that day, noticing a ton of carbon buildup on the piston face, cylinder head. In my experience, carbon buildup usually means too advanced timing (leading to the heat which cooks oil into carbon) and too-rich mixture (too advanced timing feels like running lean and most people richen up the jetting to try to fix it)

With the hi-comp head, i found that when cold, my torque was through the roof, but the heat fade was getting worse. It seemed pretty crazy, but my timing spec (.1 mm retarded from the stock setting) was apparently still too advanced. I finally backed off the timing to some eyeballed amount around 1.2 mm and couldn't believe the difference. The bike is now pulling hard all the way up to top speed, which still feels a bit lacking, but that could be due to variator tuning, worn-out-after-a-harsh-winter-outdoors wheel and pulley bearings, or the restriction still present in the un-ported intake manifold.

Also, now that the timing is adjusted properly i should be able to dial back at least 5-6 jet sizes in the 14mm bing. It isn't four stroking right now but the plug is dark and sooty. We'll see what that plug looks like after a few miles with the correct tuning, then adjust and hopefully realize some performance gains from the right setup.

I just saw someone had posted the transcription of Jenning's chapter on spark plug selection and timing advice. Great advice and a must-read for any up and coming tuners. Personally I think that Jennings book is pure gold and a a great place to start for anyone who wants to get into 2-stroke tuning, but that chapter is especially good. Its pretty crazy when a long period of trial and error prove exactly what Gordon wrote over 30 years ago, to the letter.

Busy Weekend.

2011-04-17T10:22:00.004-05:00

Pulling a couple long days here trying to get these all finished up.

From Heads

I was going to link to the category of my heads on 1977mopeds, but it would appear that they have all sold out except for the 44 mm hero puch. Wow. Or its a glitch.

Either way, Moped Factory parts are now for sale at 1977mopeds.com. I promise i'm working on the website with all the information on models, specifics, and tips for the best setup, but right now I'm pretty slammed.

From Heads

Also got a whole pile of stuff in development that should be coming out as soon as i catch up on my current production. I'll be putting out big shipments to The Treats Gang and 1977 Mopeds as soon as I make them. Rollers, Batavus stuff, and the other little random parts will be getting done soon as well. promise!

The Moped Factory is becoming a real second job for me right now, and I gotta say, as much work as it is, its pretty great to be able to make this my job. Thanks so much to everyone who is supporting me and buying my stuff, helping with development, and testing products. I'm undergoing a real tight spot right now because I'm a bit too big for my current production level, but not quite big enough to afford the equipment and help that it will take to push this to the next level. Thanks everyone for being so patient with things, I'm trying to focus on keeping my quality #1 no matter what size I am, so there will probably continue to be long waits for the next couple months while things grow. If you have any questions or want to know where your parts are at, or how long out something might be, feel free to email me.

Mopeds= Ice cold.

2011-04-12T11:08:00.002-05:00

Seriously how cool are these people?

Cant wait for rally season!

increases to the motion of ambient particles (including myself)

2011-04-07T23:05:00.003-05:00

This spring business is finally starting to take hold, and as the little particles of matter all around me increase their non-directional molecular activity, I'm gradually feeling the pull of life wrenching me from what now feels like a winter of hibernation. Funny to feel that way, as I"ve basically been as busy as humanly possible, in fact I think I'm getting enough done right now for two or three people., but I do.

The last few months here and the resulting snow melt have resulted in a near constant need to empty water buckets, move tarps, and re-arrange my already tiny cramped workshop to accomidate a constantly leaking roof. The combination of weight from snow and standing water managed to drench a lot of my stuff in acrid, sticky, vaguely organic 'roof juice' which anyone who has ever lived with a leaking roof will know exactly what i mean. Aside from the property damage, the big loss was at least 3 or 4 saturdays spent doing nothing but disassembling and rearranging the elaborately constructed makeshift organizational system at the workshop. Shelves, my paint booth, all the roof bits, light fixtures, and tarps and buckets constantly shifting to mitigate the damage from the drips which never come down twice in the same place. The 15 gallon drum i was using as a catch-all, with tarps, funnels,buckets and hoses running into it, was filling up just about once a day, sometimes overflowing and re-soaking anything near the floor. So yeah, that has been a bitch.

Good news is, the frustration of all this, plus my brother moving down with us has motivated Caitlin and I to find a house with onsite garage so i can save money on the shop and work closer to home. I'm finally back on track with the Moped Factory parts and chewing my way through a 3 week backlog. Sorry to everyone who is patiently waiting on parts for spring.

Also contributing to the backlog was me taking a week to check out the ConAg (construction/agriculture) expo in Las Vegas. This was unbelievably rad. Especially to engineering nerd types like myself who have chubbs for huge construction equipment, 2500 hp diesel engines, turbochargers the size of a dorm fridge, etc. It was great to meet so many cool people in industry doing amazing things, and so many of them wanting to hire young engineers. Definitely didn't look like a recession at the vegas expo center, thats for sure! All in all it just encourages me more to get my act together with this whole engineering degree thing and git-r-dun as they say.

On the moped front, things have been slow, mostly working on moped factory parts.. boring stuff really, not even doing r&d, mostly just stuck in production. Dont get me wrong, i love making parts especially when i know how many bikes will run better this summer because of me. Especially getting to see my parts on bikes at rallies built by people i dont even know... its pretty great, but its a lot of work and as fast as things sell out i dont ever feel the sense of completion.

I got a chance to work on the sachs for a few hours last weekend. Got the seat all set up, just need to pad it and sew up a cover now. I painted all the bracketry black because it had been rusted out by bird shit before i got the bike. I also made a really awesome air cleaner housing out of fiberglass that i'm pretty proud of. I've done 'glass work in the past but i always forget how easy it is- and rewarding. Metal can be a lot easier to work with in simple shapes, especially when you have the tools, but fiberglass is basically like paper mache' with some nasty chemicals. When done right it can yield non-structural parts in crazy geometries, which this air filter had to be. I think it will make the tuning go a lot better with a little capacitance on the intake, and the carb comes out right into the front fender, making it impossible to fit any other standard sized pod filter on there. This will bring the air intake up high, under the tank where it should stay clean and dry. Plus I want this bike to be ninja-quiet so the airbox should help with that too.

Cant wait to get this bike on the road, when i mocked-up the seat i took it around the shop a little bit and boy does it have some nuts. Probably wont be wanting to do clutch-droppin' wheelies with the touchy sachs clutch, but having that manual gives you such nice control of your clutch engagement, and it feels really unstoppable.

anyhow, i gotta get back to homework. i'll try to put up some pics so things aren't so boring on here.

Peugeot 103 Ignition coil re-winding

2011-01-26T20:08:00.009-06:00

The Peugeot 103 models made before 1980 or so were built with a very shoddy Novi brand 2 coil stator. This stator has a major weakness in the construction and design of the ignition coil, which is poorly insulated and potted, leading to erratic performance and failure. As is common on many small power equipment engines, the high tension (secondary) stage of the coil is wound directly around the primary (lower voltage) winding all inside the flywheel. After a certain amount of figuring and experimenting, I have successfully re-wound the internal stator coil to be used in conjunction with an external high tension coil, this tutorial will explain how to do this.

The first step is to remove the flywheel. Its good to use a puller for these as they are made out of brass, and mar if you try the smack them with a hammer trick. Then remove the ignition coil itself, it will be the one on top with the light brown wrapping. Its held on with 2 7mm-head bolts.

From Blog

The coil is now hanging by two wires (plus the high tension spark plug wire), one wire is 'hot' wire going to the condenser, points, etc. The other wire is the 'ground' wire that ties into the black wire coming out the bottom of the stator plate. Both of these will need to be removed and reconnected or rewired so you can cut them off as close to the coil as possible. The high tension wire coming out of the coil can also be cut off. See where that HT wire ties into the wrapping? Yeah, moisture in there was probably part of the reason you've been having problems. On my bike, before this fix, you could see it sparking all around that shoddy joint.

You can take the removed spark plug wire and use it in your moped voodoo doll, or throw it away. You dont have a moped voodoo doll? Now is the time to make one, treat it kindly and massage in fine scented oils once a week to keep your bike running in tip-top shape.

Back to the coil. Now you are left with just the coil. At its heart this thing is just a hunk of steel with wires wrapped around it. Remember the electro-magnet from 2nd grade science class- it was probably a nail with wire wrapped around it. The coil is the same thing, only instead of using electricity to pick up paper clips, your moped is using a spinning wheel with magnets on it to create an electrical charge in the windings. Basically backwards of what you did in 2nd grade.

Basically, it works like this. The 'coil' has two parts to it, just like your electromagnet. The 'Core' which is the iron or steel chunk in the center (laminated out of sheets of steel to be more efficient) is like your nail. It is the part that becomes magnetized.

The 'windings' is/are the actual wire wrapped around the core. These conduct the electricity just like the wire wrapped around the nail in your magnet.

The four magnets in your flywheel are spinning around your coil. These magnets are oriented in the flywheel to alternate between positive and negative magnetic fields. Each time the flywheel rotates 90 degrees, the direction of the magnetic field in the core switches. When the magnetic field changes, we call that magnetic flux. For some reason the guys from ICP are still trying to figure out, magnetic flux causes an electrical current in the wire wrapped around the core. Electrons get spun around the magnetic field, and the wire develops a potential or voltage.

The amount of power in the wire has to do with several factors. First, the strength of the magnets and the strength of the field in the core. You cant usually make the magnets stronger, but you can make sure this is as strong as possible by getting the core snuggled up real close to the spinning flywheel. Second, the number of wraps of wire around the core. Each wrap contributes a tiny little bit of juice, so more wraps=more power. Finally the gauge of the wire serves as a limiting factor, you can only make as much power as the wire will allow before it melts.

So, back to our Peugeot. This guy is a little bit more complicated than your standard wire-on-a-nail coil as found in puch, minarelli, etc. The high tension coil is wound around the primary coil on the same core. We dont care about that for this article. Cut it all off.

From Puegeot

The coil is coated in some nasty epoxy-like crap, a few layers of cotton tape, two layers of wire some very thin and some thicker. There are two phenolic (a brown hard plastic-like material) retainers on the ends, be careful not to break them. I broke one and replaced it with a disc cut out of tupperware lid. I found the quickest way to get the wire off was by slicing it with a dremel, but you could unwind it or cut it with a sharp knife.

When you are done you should have something like this.

From Puegeot

If you took the inner layer of fabric tape off the core, thats ok, just wrap it with a layer of hockey tape or something similar. Fabric is preferred to plastic because it will absorb the epoxy when you go to re-pot the coil.

Now a word about magnet wire. Magnet wire is solid copper wire used for winding coils. RadioShack should have it, or better yet search out your local dungeon-esque electronics/radio/etc shop. Most areas have a place like this, forgotten by time somewhere in the Tube era, when people still fixed TV's. Build a relationship with the crumudgeonly old timer behind the counter (if you are lucky he will have thick glasses, suspenders, and a beard). When dealing with electronics like one finds on mopeds, you need someone who knows how things were done 'back in the day' to ask questions of.
If he looks like this - PAYDIRT!

Anyhow, back to the magnet wire. You're looking for 24 gauge, not because that was stock but because thats the fattest wire you can fit the necessary number of wraps on the core. The wire will come insulated with a clear-ish gold/brown or red 'varnish'. You dont want the windings to contact each other, in fact, thats probably why your old coil broke- all that hair thin wire rubbing with every engine vibration.

You will have to sand off a little on the end to solder to that tab on the core. This will be your ground. If you want to keep the stock electrical system with the brake light run from the coil, you could probably slip a little shrink wrap over this and solder it to the 'black' wire... but that system is prone to BS like having your bike not run when your bulb dies, so I prefer the hard ground.

From Puegeot

Now you will start winding the coil. This is where taking your time is worth it. Nice tight wrappings, evenly spaced, are the key.

From Puegeot

You may find it helpful to use a soft tool (something that wont scratch the insulation) to keep the windings tight.

From Puegeot

When you get to the end, make a nice sharp turn around and come right back. Its important to keep the ends square and even, because they set up the whole next layer and its easy to keep straight once it is on straight, and impossible once it gits wonky.

From Puegeot

Finally you should have something looking like this.

From Puegeot

You will want to put on about 60 feet of wire, which works out to about 5 layers. This can be a little bit more, but it doesn't need to be, probably shouldn't go much less. What you are really looking for is the resistance of the coil. This will tell you the length of the wire.

Use some tape to hold down the loose end of wire and measure from that end to the ground wire.

From Puegeot

You are shooting for 2 ohms. More is OK because it means more wraps, but too much could fry your points or HT coil. Try for 1.8-2.4 ohms.

Finally after winding the coil, wrap some fabric tape around the whole coil. Fabric is the best because it will absorb any potting compound and turn into a fiber-glass like hard shell to protect your electrics.

From Puegeot

Now that your coil is all wound nice and tight, you'll have to get the power out of it to the rest of your electricals. You'll be sanding off the insulation again and soldering a lead on to the loose end of the cable. You can also solder it to the stock tab if that is still in place lodged between the layers of phenolic on one of the ends... thats probably the best actually.

From Puegeot

The next step will be re-installing the coil. This will be done by running a 'hot' wire out from the soldered tab and cleaning up the stock wiring. You will also have to install the high tension coil. Since the internal coil is designed for a Bosch (puch) system, you can use the bosch coil, or you can use the generic one, or do what i did and get a minarelli/CEV/Ducati coil and the bolt holes line up with the mystery bracket on the swingarm! The new wiring diagram will look something like this:

From Blog

Now, thats a super simplified diagram. I'm going to run a 12v rectifier/regulator on mine for brake, tail and headlights, but you might want to do something different. If you saved a ground lead as seperate you can probably hook that right up to the stock black wire that is there, and get a working tail light or brake light or something.. i dunno. Try it out.

Once everything is together and working, now would be the time to go ahead and pull that coil out enough to pot it. Potting is just applying some sort of glue/varnish/etc to the wires so they dont rub on each other with engine vibration and wear the insulation off. Crazy wayne suggested fingernail polish (you could also add a nice touch of color to your stator this way- use matching shrink wrap tube!) or varnish, polyurethane, epoxy, fiberglass resin, etc. Probably anything that is heat and water impervious.

When you are all said and done, your bike should look something like this... with a nice fat ignition wire that wont get cranky in the rain:

From Puegeot coil re-wrap

Pro tip: use a little di-electric grease on the spark plug wire when you install it, and finish it with either heat-shrink tube or use the stock rubbers with a tab of silicone gasket seal inside them.

Dont forget to set your timing when you replace the flywheel!

Good luck and happy blastin'

Special thanks to Mark Hand for the excellent photographs and Michael 'mike' Naz advising/answering stupid questions.

for more discussion on coil winding:
Re-wrapping the HPI light coil
Peugeot coil winding success!

Snowpedding, subarus, etc

2011-01-24T23:56:00.003-06:00

This blog is serving as a reminder of how out of mopeds I've been lately. Well, I dunno about that out of mopeds, i mean i'm still riding, just not getting as much wrench time in as I would like.

I am still riding, which is more than most of you northerners can say...

Its not very interesting, my batteries were dying but it was a somewhat sketchy ride home. The first few big snowfalls of the year always seem to be the worst, this year the snow coming very late probably made it even worse. The drivers are all going super slow, you forget not to use your front brake... etc.

Anyhow that was a week or two ago, now snow, slush and salt are de rigeur (i think thats the term i'm looking for) for this part of the country. I'm really liking the Peugeot in the crap, variation has its advantages, keeping me from sliding around as much, but i really hate the dry clutch and the bike still needs some tuning, the low end grunt that i'm used to from my maxi ZA just isn't there for plowing through snowy drifts, and the clutch wants to drag and push when you try to slow down. Plus the belt gets wet and slips a lot also... ok so i guess this really isn't a great snowped.

I was hoping to have my other ZA built and ready for the snow so i didn't have to abuse this poor pug to the salty badness, but oh well.

School has been busy. I should be doing homework now but i need a break.

In more good news (also somewhat related to moving around milwaukee in the snow) I got Caitlin a new car... We're now a TWO subaru family! how great is that!

From Blog

I picked up this slightly beat 1993 legacy sedan last weekend. Well not the one in the picture, but almost the exact same. This has a little rust in the corners, but all around not bad. The Peugeot 505 SW8 was just not cutting it for her. The rear-wheel drive isn't bad for slipping around (it has a LSD in the rearend) but getting it stuck between berms when parellel parking was a nightmare, plus little things like the heater blower motor going out at the beginning of December and having to drive around the state for Xmas with no heater, were starting to add up to me being annoyed.

Plus i got a pretty smokin' deal on this car for $300. The pre-1994 (post '89) subaru legacies have the best powertrain subaru ever put in anything... as far as reliability goes. Subaru, doing everything different, decided to come out of the hole building the best motor they could, then progressively making it worse with head gasket problems, a crappy auto trans behind it, etc. This car is basically the sedan (boy i'd rather have a wagon, but oh well) high water mark of 1990's Subaru.

It needs a new exhaust, and it made it home with a leaking tire and 3.5 quarts of oil less than it should have had, but like i say about 5000 times a day lately, "I'm working on it, I'm working on it..."

Get ready to waste a few hours here

2011-01-12T09:59:00.002-06:00

I try not to re-post much from the internet, but in the absence of any fun pictures in the last post (for some reason my computer stopped recognizing my SD card) I figured I'd send some folks over to this site for some moto-porn.

http://elsberg-tuning.dk/

Big block chevy's, sick 50cc's of all breeds, and a ton of photos I've never seen anywhere else. This stuff is really amazing, probably spent a few hours already looking at all the cool stuff this guy has posted.

Really amazing to me to see all the different ways people have tried to get more power out of 50cc engines. I think the challenge of working within a very limited format forces some of the most innovative ideas and gives creative engineering types a chance to test ideas.

I've recently become infatuated with a technology known as 'Fuel-Air stratified turbulent' injection... stupid acronym that really doesn't explain what is going on, but I'm going to try to convince someone here to let me implement it on a 4-stroke engine for the high mileage vehicle. It was designed for 2-stroke scooters by piaggio... long story short it is a mechanical direct-injection system that requires no electricity and can run up to 10k rpm... unreal. Not much for performance gains, but the fuel economy is through the roof.

more on that later...

Holiday 'vacation' recap.

2011-01-02T15:01:00.006-06:00

Wrote this a week ago, was waiting on some pics to post, guess i'll add them later...

Having the last two weeks off school has been nice, not quite as productive as it could have been, but thats the holidays for ya. I guess its supposed to be a vacation, but I've been working harder than usual to get some long-awaited projects finished up by the end of the year. Starting out with a very ambitious list in my little notebook, I'm happy to be able to say I checked off most of the boxes.

The Cranks hosted the third annual 'Fond-of-dudes' party with record attendance. Cool to see folks from Chicago, Madison, and Minneapolis join the merry-making this year. Good party with lots of food, but next year we'll do a better job of coordinating fondue pots.

I finally got around to machining the final few bits for the long-running stock Vespa project. I had to re-located the ring land pin, so i figured while i had the piston in the horizontal-axis rotary-index table-chuck-thingy in the mill, I'd use a 1/16" end mill to add some ring-land gas porting, or "BigBlockFiero Tech" as it is often called on the MA forums.

This is an idea seen on all sorts of pistons, mostly in 4 stroke applications, where the biggest advantage is better ring sealing. On a two stroke, the theory goes, that putting 'ports' into the upper face of the ring groove allows for gasses to escape around behind the ring on the down-stroke and deposit more oil on the piston and cylinder walls, cooling the piston. I've spent a lot of time mulling this over in my mind. Its a tricky thing, interpreting the theory and actual results, because tighter ring sealing is very important in piston cooling. You see, in a running engine you dont want any gasses between the piston and cylinder wall. The piston cools, primarily, through the cylinder wall, and oil conducts heat better than air. If you get any blow by you will run a lot hotter. In fact, i've seen a lot of piston seizures that show bad break-in or bad ring sealing and a lot of blow by, leading to carbon which further insulates the piston and cylinder wall, and gas insulating the piston and cylinder wall.

So for my money, I'd bet what we are really seeing with ring-land gas porting is a better piston ring seal. The down side to this is the greater pressure supposedly wears out the piston ring faster, although if done correctly I find it hard to believe it will make much difference. I've run the same rings for 10's of 1000's of miles with no problem on bikes before, so its a compromise i can live with if i burn out one ring at 2000 miles or so.

Anyhow, to make this all work you need to only run one ring. I was planning on doing that in the vespa anyhow because both the ring gaps landed right in the 3rd and 4th transfers I cut in. To replace the ring locating pin, i machined one out of brass. 2mm diameter, and pressed it into a 5/64" hole- which works out to 1.98mm and change. The pin went in with a little pounding so hopefully it will hold... it would be pretty depressing to shred another piston and cylinder after having put over 10 hrs of time into this setup. Especially considering that the last piston and cylinder lasted all of one trip around the block before I broke them trying to fix them. It would be pretty sad if i was also destroying $130 kits each time rather than free doorstops.

Everything finally got re-assembled on Friday. The vespa kicked right over and ran good once warmed up. I think i drilled out the atomizer tube too big on this one, because the low end has never been good, but now that i'm running 20 deg of blowdown and 158 deg of exhaust timing, its not expected to idle very well at low end. The clutch still grabs too early in my opinion, but hopefully once i get some more low-end back from tuning carb and ignition, it will have power to slip the clutch at lower speeds. The last time i had it together it was smoking the belt instead of slipping the clutch... stupid dry clutches. Once i get things dialed in i'll probably go to a larger diameter belt. I'm also looking at modifying the stock clutch by lightening it and adding some cooling fins, also machining out the belt groove so the wider belt will sit deeper and keep the dimensions the same, or even lower the gearing.

Also had some time to work on the Sachs, mechanically it is pretty much buttoned up. I had to add a small jumper chain for some reason... not sure why the chain got 6 links shorter from the 505/1C to the /2BX but thats how it goes sometimes. Got the chain on and squared away. Also finished up all the cable routing and such. The clutch and shifting is very smooth and accurate, but i can tell already that first gear is going to get annoying as it seems to require more articulation of the shift grip than neutral and 2nd. I wish the 1st/2nd positions were reversed. It was obviously designed with 2 as the 'main' gear, and 1 as a 'granny' gear for getting up hills and the like. 2 is the default position if the cable breaks or what not.

The way i have the gearing set up with a tomos 28 tooth in the rear and the standard 11 tooth up front gives it a standard-ish 1st gear, feels like maybe 16/40 puch gears. A big jump from the stock 11/43! This engine has so much butt-wrenching torque, i'm hoping to set this up with city/highway gears so i can shift comfortably at about 45 mph and pull up into the high 50's, low 60's without winding the piss out of the motor. Gonna be hard on the clutch, but being a manual I think smooth gentle shifting will prolong the life. When it does fry, i have a few tricks up my sleeve i'd like to try. The last straw being to completely drill out the output shaft on the crank and press in a splined 4130 shaft to adapt to a totally different(reinforced) clutch hub.

Since I'm building this to be a 'touring' bike- for long distance adventures and camping trips- i'm working on a slew of attachments starting with a large and very sturdy seat. To keep weight low I fabricated it from 3/16" sheet aluminum. Starting with a posterboard pattern, tracing and cutting from sheet metal, finally bending it up and welding the seams.

I'm getting much better at TIG on aluminum, but still not super happy with my results. Aluminum is a tricky son of a gun and demands perfect cleanliness and good fitment. Getting better with TIG I'm able to fill gaps better, but its hard to fill gaps and make it look good. Oh yeah, and make it strong, that is important too. Anyhow, the seat turned out pretty good. The bike is designed to have the weight on the seat post so I had to make a steel rib to transfer the weight onto the tube frame, and it should be strong enough to let me use the seat (probably tying in where the seat attaches to the luggage rack) to build a racking system. I would really like a retractable rack for carrying cases of PBR, and rails making it easy to attach and detach side bags.

I've also been thinking a lot lately of some sort of trailer hitch. Possibly using a piece of very stiff hydraulic hose to act like a ball hitch, but with a bit more control. Ideally I'd like to be able to tow a trailer that would be able to carry another moped like a 'tow dolly' so i can pick up broken down mopeds or transport them around without a car. Anyhow, maybe by next summer. Either way being able to fabricate aluminum will be a big help as it would be way too heavy to make any of this junk with steel, and aluminum doesn't rust. It is expensive if you buy it from the metal rack at home depot, but if you go to a good scrap yard, especially one that deals with industrial scrap, there is tons of it laying around they will sell you for the same scrap price they paid for it. I've found lots of good useful metal this way. Even built a copper still once from a scrap bin.

For Moped Factory work, I finished up a huge order over break and started work on some of my next round of projects. Another level of sophistication with some real top-notch performance parts. I'm trying to make headway on the moped factory blog as well, to try to get as much product information out there as possible.

Oh my gawd!

2010-12-16T12:11:00.002-06:00

I just found this via the excellent Corpses from Hell blog.

Imagine going a buck-10 on this thing at full tilt around a board track. It brings a tear to my eye just knowing that happened at one point. Really makes the ol' grapes sag a little bit hearing that amazing engine let loose- can you even handle thinking about what it would be like to see/hear that in person? And 10 or more of them no less! No wonder America was once the most bad-ass country in the world.

Peugeot Coil Success!

2010-12-12T19:39:00.005-06:00

FINALLY!

After about the 4th time re-wrapping this son of a gun I finally got it to fire and damn, is this thing kickin! I'm going to re-wrap all my coils from now on. I got too carried away with the excitement of everything finally working so i completely forgot to take enough pictures but I can at least explain what happened and what i did and all that jazz.

From Puegeot coil re-wrap

So the first time, i did this pretty sloppy, twisted together wires a bunch of the connections, wound the core sloppily and fast just to see how things would work. I used the 'black' wire that was connected to the 'ground' of the coil as my new live wire coming out of the magneto, to keep the grommet. I attached the hot off the coil to the purple wire in the puegeot stator which goes to the points/condensor. I also unhooked the brown wire that goes to the little brown resistor thing... no idea what that does. The other side of the coil was grounded soldering the magnet wire to the tab. I also had to replace one of the phenolic circles that border the coil with a couple rounds cut from the top of a tupperware.

I attached an old italian 1 wire coil to the mounting tab on the swingarm- perfect fit! I ran a ground strap from the mounting bolts on the coil to the frame. I used a nut on the intake manifold but it would have been much easier to tie into the grounding strap that connects the engine to the frame (dark blue w/ spade connector). Might do this later if there are connection problems.

The first winding gave me about 4 ohms of resistance through the coil. I was shooting for a replica of the Puch coil by matching the diameter of the wire after winding- which is 24ga and gives 2 ohms. Like i said, this was a pretty sloppy winding job, so i pulled all the wire off and started again. It was a lot nicer job this time, and had me at 2.6 ohms but still not perfect and even-like.

At this point, i took a second and shored up all the connections, soldered everything together, and did a much more careful job of setting the points and flywheel position to get the right dwell, because i was worried that might be a problem. I checked and re-checked my resistances. Still no spark. I was getting frustrated because i cant afford gas to be driving a car all over for another week, so i tried putting a Puch coil in... that didn't go so good either, long story but its really not a very good solution to this problem at all, you have to drill the holes out pretty big to get the right air gap, and space it with washers, and its a pain to drill because its a laminate... plus the curvature of the core is wrong for the larger diameter flywheel on the puegeot.

So i bailed on that idea and went back to winding again. I took the wire off that gave me 2.6 ohm. This time i was very careful and went a lot more slowly and wrapped it nice and even. I also used a lot more tension to keep the wrappings tight and the wire straight. I started with the side with the tab (right hand looking at the stator) and soldered on the base of the wire. The center of the core had previously been wrapped with electrical tape, but in hindsight cloth tape like you put on hockey sticks might have been better, the electric tape is too mushy. You need to start with a very sturdy base to make sure the wire lays evenly or it will be all messed up. The ends are the hardest to keep even so be extra careful. Then i wrapped it clockwise holding the 'ground' end in my little drill holder magiggy.

From Puegeot coil re-wrap

I dont know how many wraps or how long of wire i used, sorry, i should have been paying more attention, but it ended up about 3/4" diameter. I was measuring it by the resistance.

At the end of the wrapping i slipped some shrink wrap over the hot lead and wrapped the whole shebang with a tight cover of electrical tape. The coil probably should be potted with epoxy, but seeing as this is an experiment i wanted to get it working before setting things in stone, er, epoxy.

From Puegeot coil re-wrap

Once everything was wired up perfect-o i replaced the flywheel, set the points, and spun it with a drill to see if it was sparking. Holy crap! The spark is like nothing i've ever seen on a points system. Super hot, making a sharp crack, and almost like a flame thing where it comes out of the wire. It can jump over 1/2" as opposed to the old ignition that could barely jump .016" spark plug gap.

Once i got the bike all back together ( I also had to fix my busted exhaust pipe flange) it fired up just by pushing the pedal by hand. Barely one turn over, cold.

I brought it home and rode it to work today, took a little bit of persuasion to get it to fire, what with it being 8 degrees out and all, but it lit up pretty easily and is running much, much better in the low end. The acceleration from a dead stop, especially under load, is amazing. The hill in front of my house that i couldn't get up before, i can now ride up from a dead stop.

This is an awesome mod, and if you have the patience to do it right it would be pretty easy, it took me 4x as long because i was being impatient and sloppy. I still have to hook up a tail light, brake light, and (probably) some sort of voltage regulator to get the whole system up to 12v spec after gutting the electronics, so i'll keep updating this post as things come along.

Peugeot coil fail

2010-12-10T13:50:00.002-06:00

BAH! Spent the whole morning yesterday untangling a huge rats nest of magnet wire, then wrapping it onto the peugeot coil core, then installing the coil and trying to get life out of it... nothing. bummer. It has continuity and measures about 5 ohms of resistance. This seems kinda high to me, i'm shooting for basically a slightly hopped up replica of a stock puch coil which measures 2 ohms.

I talked to some EE's today at work about coil theory, i guess the EMF or whatever it is that moves electrons in the wire of the coil, will be forming a rotational force (kindof like a torque) around the axis of the core. I knew this already and it makes sense, but i hadn't thought much about it. That means that the smaller diameter of the core, the more current and less voltage, which is not what i want, i think, because i'm looking for high voltage and low current... although they are related by resistance in the HT coil primary winding. This is all very confusing.

Bottom line, i need to re wrap the coil, but this time maybe go slower and do a more orderly job of wrapping the wire. I dont think the direction matters, but who knows. I grounded one side of the wire to the core itself and ran one side to the High tension primary phase (along with points/condenser). then grounded the high tension to the motor and tried to measure VAc with the points held open. Nothing. Shoot, i would have hoped to at least see a little juice.

I really need an o-scope or maybe just a 'not 3.99 harbor freight' DMM... I'm starting to think I'm a bit out of my league with this project, but seriously, how hard can it be, its just a coil of wire around a steel core, right?

Hopefully i can do more 'spearmintin this weekend.

Everything all at once

2010-12-07T21:17:00.003-06:00

So the last couple weeks have been a real mess. Not much time for moped fun, mostly moped work. I've done quite a few custom heads, and finally shipped out some one-off parts that I've been designing to see how well they work and if it is something worth putting into production, but other than that things have been super boring.

Its been probably more than a month since i was able to update this last, finals for fall quarter killed me pretty bad, then it was two weeks of working and driving all over the midwest to hang with bandits for tanks'd'giving

This guy is great... there are very few things that i would drive 16 hours to attend for 12 hours, but campfires and garage bullshitting with the bandits is always worth it. The narrow window between finals week and thanksgiving break allowed me to attend this one with a clear conscious knowing i hadn't violated my 'no rallies during school' policy that has so far kept me from getting any moped-related F's. woo-hoo!

The next weekend saw me back up in the frozen northland, visiting the family in Eau Claire. Its always good to be 'home' especially when you come from such a warm familiar hallmark-esque town such as the Eau C.
Plus 2.50 mixed drinks and $9 pitchers dont hurt. The Joynt and GI are two of my favorite bars in the world, miss them lots.

I finally got serious about ironing out the bugs in the puegeot, the cold weather has aggrivated the wierdnesses and keeping it outside really hasn't been very good for it. I finally pulled the coil out last weekend and cut off the windings, so now i'm committed to re-winding it. I got the drill-mount jig ready to go and found some 24ga magnet wire. Trying to learn something about fluxes and potentials and all that crazy physics (why is it i've had years of these classes and cant do anything practical with them!) right now to have a better idea of how much to wrap. The 'more is more' school of thought has occurred to me, but i really need this thing to get me to and from work so i want to get it right the first time. Walking/biking/bumming rides from the GF is getting old quick.
I've also been thinking a lot lately about needles and atomizers and bing carbs designed for piston port engines. I've modded the needles a little bit to make up for porting stock cylinders, but i've never ran a bing on a reed motor. It could be some of the wierdness i'm experiencing is related to all that atomizer/needle business being all wrong. I gotta get the coil fixed to be able to tell though.

Also, the stupid pipe which has been cracked and poorly spot welded onto the nut itself for 3 months now... gotta seal that up. machined a little adapter thing that will weld to the old pipe and give it a nice new machined (100x stronger) lip to securely bolt into. That might take care of some problems.

Thats about it for me. oh yea cranks are official. thanks a million to everyone who voted for us, hopefully we wont embarass y'all by acting like a bunch of nerds. oh wait we ride mopeds, why is that cool again? also, does anybody besides a handful of members on the coasts who are in MA for strictly social reasons, really care whether or not mopeds are cool? I'm happy with the members forum joking about us being the 'kids at the magic table' of moped army. I think moped army should be about the kids at the magic table. I wasn't really one of them because i have no patience for card games but i've been to my share of drug fueled LAN parties and we were having hella more fun in high school than the 'drunk-in-a-backseat-trying-to-feel-up-a-passed-out-cheerleader' set.

And while i'm ranting:
Also, Four... anyone who is bitching should blame the lawyers and politicians who give them power to sue over stupid things like underage people drinking way too much and shooting themselves in the head. Thats what killed four, not the governments or alcohol control boards, the company was afraid to sell the product because of a lawsuit and fear of more lawsuits. The same thing that happened to Sparks (RIP).
Any time you cheer lawyers 'sticking it' to big awful corporations, remember those corporations are in place because they are making a product people want. Lawn darts, hot coffee, blackouts in cans (or bottles as they have been traditionally served). Irresponsible, opportunist and unethical Lawyers screw the pooch for all of us.

Ach... i'm too hostile to be typing tonight, back to the grind.

Batavus go-fast parts are in testing, look for some cool stuff soon.

Good Housekeeping

2010-11-03T16:36:00.002-05:00

2 quick things:

1) I have some heads for sale on Moped Army buy/sell

Aftermarket 'treats' Hi comp 50 and 70, $25 shipped. The 50 is in perfect cond. The 70 was a little beat up but i re-faced it on the lathe.

Batavus M48 hi comp 50 cc. I think i decked this about .025". They can go a lot further, but this is definitely a noticeable gain especially on the upper midrange where these things have no power whatsoever.

#B) Thanks so much to everyone voting for the Cranks this round of MA branch review. Two handsome and fabulous Mosquito Fleeters even put us in their blogs. The warm fuzzies are just flying around the interwebs, getting stuck in the nooks and crannies and in my butter There are a lot of REALLY AWESOME GANGS applying for MA Branch Status this year and we Cranks are so honored to have the chance to apply. Thanks for all the kind words and supports MA, hopefully we'll get in and can continue spreading the love and warm fuzzies.

See you midwest cats in louisville at thanksgiving!

Super Sketchy Brah.

2010-11-03T16:21:00.004-05:00

Seeing as Cristophe put up some sketches of far off projects (maybe his isn't very far off) I guess its ok for me to show you what i've been doodling when i should be doing my homework.

Maybe recent posts on the forum will tip someone off as to what this is... I've been thinking a lot lately about finally building a top tank. MB5 or maybe CBR125 forks, swingarm (monoshock) wheels and a motor to make it worth it. Something I could practically and reliably ride on the highway or race on some of the local underground TT races. I love the idea of using scooter parts, especially variators so i can fix the engine. I definitely get off on the engineering and pioneering aspect of this kind of thing, and it would be a blast to build my own engine, do some finite element analysis (a class which i am taking and loving the crap out of right now) and have a crankcase CNC machined from billet. Send out for some heat treating... the works.

Who knows if anything will ever come of it, but it never hurts to dream. Maybe Project 'MOPED FACTORY PHASE 2: Return of the Profits' will net a little extra walking around money while leaving me with some spare time. Ha yeah right.

Ch-ch-changes

2010-10-27T11:31:00.002-05:00

Ugh, i'm obviously not a graphic designer, and aside from being able to slang HTML reasonably well, i'm not a pro website 'make-look-gooder' kinda guy, but the colors and format and stuff on this blog are really gross and make me not want to read it myself.

so i made some changes, might actually look worse now, but who knows. I should just have a blank page up with some text, but i'm too lazy/busy to even do that.

i'm machining heads and making parts like crazy this week, trying to correct the proportion of internet mopeds to real life mopeds. hopefully by next week some new stuff will be in stock at treats, or at least re-stocked... sorry to everyone who has been waiting on goodies.

Puegeot Power!

2010-10-11T09:14:00.003-05:00

In other words, the Peugeot is running well, finally! The last time I blarged it was way off, but turns out not so much really. Four stroking in the midrange had me dropping the needle all the way down lean. The bike was trying to tell me something was wrong because it kept puking out the throttle cable. Finally in an act of desperation I tried putting the needle medium-rich and now it is running beautifully.

I moved the timing a couple degrees off Shaw's suggestion of 15-17 BTDC, which might be wrong now giving me lousy low end, but who knows, I did port the cylinder pretty aggressively, plus I haven't tuned the clutch or the variator yet.

Here's how she's sitting right now.

From Puegeot

The pipe clearance is dead on.

From Puegeot

The porting was strictly 'seat of the pants'... I stayed pretty conservative because this is supposed to be getting set up for my girlfriend, but stock porting on these is pretty weak. I figure I can make up the loss of low end by tuning the clutch /variator, because right now when that clutch grabs it almost stalls the bike.

From Puegeot

Yep yep, pretty good stuff. Gonna be gettin' smashed this week, Wednesday I have 2, 2 hour midterms that are going to crush me. I probably have at least 10-15 hours of learnin' to do by then. Maybe thursday and friday i'll finally be able to dig myself out of this hole and make some magic happen. New developments on the Moped Factory front are in the works, but i'm pretty much broke so it is making purchasing raw materials difficult/impossible.

Slavin'

2010-10-05T19:14:00.001-05:00

School is kicking my ass.

The maxi blew out the brass bushing on the end of the crankshaft (after 15-20k miles of abuse) and for some reason i cant seem to break the counter-shaft nut off to get at it. So i've been riding the peugeot, which is running better but still really crummy. Dead spots all over the power band, very little power. I ported the cylinder a little bit just opening the exhaust and eyebrowing the transfers, which pulled up the top end but now my low end really sucks. Its jetted at about an 80, with the needle all the way lean, and running really wierd.

I think its definitely time to re-wind the ignition coil. Shaw suggested i just cut off the outer windings, which would probably work well, but i'm going to kick it up a notch while i have everything apart and re-wind it with heavier gauge wire and maybe a few more turns. Hopefully that will solve all my problems, but who knows. I'm not sure what stock compression is in these, but it feels pretty good. I might try milling the head a little bit, but its not high on my list of priorities.

I needed to take a break from homework a couple nights ago so i made this... pretty much sums up what my life has been about the last 3 or 4 weeks.

Boys of fall

2010-09-13T15:15:00.003-05:00

From saltyfest

I remember being a kid and really hating fall. The beginning of school, the end of summer, weather getting cold. A real drag. Lately this has been changing for me, I really have come to love fall. Dry air, a chance to wear all my snazzy sweaters and cold weather duds, and finally camping without having sweaty sleeping bag stuck to you.

From saltyfest

Last weekend was truly the best of fall in wisconsin. SaltyFest 2 was all that makes mopeds great, with good friends, cheap booze, beautiful country riding and, oh yeah, 100s of cars getting smashed. Not enough you say? How about this FREAKIN JET CAR!

From saltyfest

Oh yeah, its melting two cars stacked on top of each other. MELTING THEM! They dont do this in france, son! Only one country has figure 8 BUS RACING!

From saltyfest

Figure 8 Trailer racing! Some crazy dude jumping a ford tempo off a moving ramp at like 60 miles per hour. THIS IS THE USA BABY! Where's my bruce springsteen when i get all jacked up on america 'n stuff.

Christine and 'her girls' got radical on some shots!

From saltyfest

We drank like 20 pitchers, or maybe more like ten but it was a lot. Oh yeah, fireworks too. Super rad weekend, thanks again Salty!

Two steps forward, four steps back

2010-09-09T09:12:00.003-05:00

Awesome wednesday night ride last night.... well not super awesome because I'm still pretty sick, and was being kinda a party pooper, but the puegeot finally made its Wednesday debut and was cooking along pretty well, definitely keeping up with the pack. Its really hard to get a feel for how fast this bike is because it is so quiet and doesn't really rev out or have the raw torque i'm used to from my maxi. The engine is eerily quiet at full speed, which is probably somewhere in the upper 30's.

It should have a lot more in it with proper tuning. I'm also not sure what the exhaust port looks like in these things stock, but the way it dies on the top end, i wouldn't be surprised if it was pretty restricted. Seeing as most accounts have them doing about 35 all bone stock, i've probably got a fair bit of tuning to do before its running at full potential.

In other news of awesome, the Sachs is running. I spent about an hour on it yesterday. The spark was weak and intermittent so I poked around a little bit and found that the internal coil unit was way too far away from the flywheel. I popped the flywheel off and used my masking tape trick to get the coils crazy close for maximum magnetic fluxin'. There is no flywheel key in this because i got it from crazy euro kids who dont believe in that sort of thing, so the timing is kindof a guess. There are timing marks on the flywheel but who knows if its in the right place. Either way everything looks really good and its now blasting out a fat blue spark.

True to form for this awesome kit, it fires up halfway through the first kick. Even with a massive air leak due to a missing manifold bolt it popped right to life. For some reason the chain i took off it is way too short... cant imagine how that happened seeing as it should be the same exact gears and motor from 1 speed to 2 speed, but somehow i'm about 7 links short so i decided to go ahead and put the tomos rear sprocket on. At first glance these looked compatable, but trying to fit them i found the tomos mounting bolt holes are a smaller diameter pattern- crap!

Since this is a fairly important part, i dont really want to fudge it so i think i'm going to rotate the sprocket 90 degrees and drill a whole new bolt pattern using the indexing table on the mill. I might also upgrade to a slightly larger bolt (maybe SAE rather than metric) because the little cast nubs inside the hub that are supposed to hold the nut when you tighten the bolt are all ground off from having changed this sprocket many times. All they do now is prevent the use of a socket wrench to hold them.

Either way, a productive day. Not sure if i'll have time to get both the puegeot dialed in (including switching out handlebars) and finish buttoning up the sachs all in one day before Saltyfest this weekend, but it looks like this chain/sprocket thing is going to dick me... oh well, looks like i'm moving the release date on the sachs back to bombourbon run. That will give me time to design/build the ultra-luxo-cruiser long seat and modular luggage system i've been fantasizing.

FACO power for le peugeot

2010-08-17T08:51:00.009-05:00

This pipe has tempted every Peugeot owner since it came up on treats and 77 a couple years ago. Its unreasonably cheap, looks like it should mount with minimal complications, and from the pictures appears to be a halfway decent shape for stock-ish bikes. The scary part is that there is almost no information. I got my first Pug a couple weeks ago, and nobody could say for sure 'I've ran this, its good' besides somebody saying Fred (all your moped are belong to us) had a couple bikes running mid 50's with them, kitted.

So after a couple days of homework, i took the plunge and invested the 45 dollars in it. When it showed up I measured it. Here are the measurements:

Faco Dimensions

It looks to be about the same as a puch proma GP, maybe closer to a Jamarcol.. never measured one. The only dimension that is really wrong is the convergent cone. This one has a sharp taper and is only 4" long. In theory, that should result in narrow powerband that shuts down abruptly, not exactly what i'm looking for on a stock bike.

The other thing i noticed right away were some suspicious-looking spot-welds right in the belly section of the pipe. Since i knew i wanted to build an integrated silencer and i wanted to re-do the convergent cone, I figured i might as well get to hackin' to see whats up with those spot welds.

I also mocked up the pipe on the bike and found out that the mounting brackets are too short. The flange wouldn't sit flat, and the belly of the pipe was hitting the little nub that holds on the flywheel cover. Might be designed for a knock-off of the puegot with a CDI stator, or something like that. Either way, it needs about 9/16" added to each of the mounting bracket arm thingies.

After chopping the pipe in half i found this:

From Pipes

Oh man, that sucks, not only is it almost impossible to remove without chopping a huge chunk of the belly section out, but it is most certainly a major restriction. It pretty much defeats the entire purpose of an expansion chamber and turns this into a stupid looking muffler that doesn't muffle much. If I didn't care, i would probably just cut out the inside of this with a torch or something and weld the pipe back together as it was, and slap an aftermarket silencer on it, but i like skinny long pipes for stock bikes, and this looks like with a little work it could be really awesome.

So i cut out the restrictor, and lost most of the belly section of the pipe. In order to get the integrated silencer to clear pedals and stuff, i had to cock it out so i beveled the cut a bit outwards and welded in a new chunk of belly section, a bit longer than necessary. I formed a cone out of some sheetmetal for the convergent cone, and welded that to my new stinger, which was drilled for perforation. The new convergent cone is a bit longer and has a larger stinger outlet, hopefully giving the effect of a longer duration power band.

I test fit the pipe, and now the angled belly section was hitting the little nub on the stator where the rubber tab bolts on. Easy fix- put the pipe in a vise and bend the header and all the mounting tabs over, so now the pipe is tipped down a bit on the outlet side. The stock mounting brackets should do the trick now also, because i dont have to drop it down to clear that nub anymore. The muffler has to come back up to clear the 2.25" gap between the pedal and the kickstand, so I welded the cone back into the belly section tube with a slight up-kick. I'll have to put a turn-down or something on the end of the stinger to keep from greasing my rear wheel but no biggie.

I've also gone to a smaller muffler canister, 1_3/4" tube instead of 2.25 to clear the pedals a bit more easily. The sound dampening might not be as good, but it will still be better than those proma circuit exhausts.

From Pipes

As of now, its mocked up and tacked together. I'll test-fit it tonight. I've hooked up a 14mm bing carb with a shim to the stock intake, reeds. Hopefully this will have things running well enough for tomorrow night, and we'll be able to do a little shakedown before grand rapids.

UPDATE 8/19:
Mega boner kill, Caite and I had a serious talk yesterday at lunch and decided we should probably pay the power bill instead of going to Grand Rapids. It would be fun, but both the Sachs and Puegeot are in the early stages of tuning and probably not rally-ready, we're both broke, and I have a huge backlog of work to catch up on from summer vacationing too much at the beginning of the month. Maybe if my paycheck comes in tomorrow and is huge, i'll hop in someone's van at the last second, but its doubtful.

The good news is that the pipe fits perfectly. It variates perfectly through the gap between the pedal and kickstand. The bike fired up on the first kick, and revs out like a cross between a wounded cougar and a chainsaw, but something is keeping it from idling, possibly timing, possibly something having to do with the super random assortment of bing parts that i turned into a carb. The pipe is amazingly quiet, like, quieter than a tecno estoril, quiet.

The fan wasn't working in the workshop yesterday (again) so between a kinda-iffy bing needle and lots of exhaust fumes i couldn't get things dialed in before i asphyxiated myself. Pictures and final tuning results later tonight, maybe I'll get the sachs cabled-up and assembled a bit too.

Update 8/23:
Finally got this thing running pretty well after replacing the condenser. Small job turned into 2 hours of beating on a flywheel with a hammer because i didn't have a peugeot puller. Damn. Its running a lot better, but now it seems rich. Its running a 70 jet in a 14 mm bing, which would be huge for a stock/piped puch, but its really bogging out bad on the top end. Methinks timing might be way too retarded at 1.65, or maybe it really is sucking in that much air. The variator is also pretty much useless with the current weighting because it variates way under the power band of the pipe. That needs to be fixed as well. More later

Bonus: the sachs is fully cabled and almost ready to run, the shifter cable is perfect but it keeps slipping off, i'll have to do something about that.

Update 8/24:
Awesome success last night, finally got things running perfect-o, blasting right up to a solid 25 then slowly climbing to about 35... meh, sounds like those tiny little flippy-flappies are choking me out. it four-strokes like a mother when it revs out on the stand.... yep, restricted reeds, indeed.

luckily my patron saint, blaze, lent me some nice generic black plastic reedy things, until i can get some thinner gasket paper and chop up my flap-holes. frabjulous!

maybe wednesday i can duck out of work early and finish the sachs, it is so painfully close right now. shifter, clutch and everything seem to be working good. still have to find a plug for my voltage regulator chinese scooter special, and do a tiny bit of rewiring for the 12v system. oh yeah and the pipe needs a little persuasion as well.

More new products!

2010-07-28T14:50:00.005-05:00

I've been flogging the hell out of my poor little kidnapped Keebler Elves and managed to squeeze out a few new products I'm super proud of. Both should be top sellers in stock at Treatland soon.

First, the 'treats reed kit' aka 'tomos alukit machined for puch exhaust flange' has a major design flaw, the deck height is about +3-4 mm from the top of the piston. Ohnoes! Low compression to be sure, which is a major bummer for a kit with awesome bottom end. I built one of these a few months back and tried a couple different things to get it in spec, but the easiest solution i found was a super-duper high compression head.

From Puch 'treats' reed kit - Noah Bern

These are machined from puch Magnum heads, which fit the fins relatively close

From Puch 'treats' reed kit - Noah Bern

Not perfect, but the performance increase is noticeable. Starts much better, timing is more predictable, and it feels like it has way better torque, but that's hard to claim without a dyno. Anyhow, about 4 of these are in testing and have been running great.

That build also made me re-think a big problem area for owners of magnums. Over the years I've tried a few different ways to mount maxi exhausts onto magnums, including flat brackets with bends, different shims, etc, and nothing has been satisfactory in terms of looking clean, simple, and fitting a variety of different bikes, kits, and pipes. Finally I came up with this little guy:

From Puch 'treats' reed kit - Noah Bern

Simple, elegant, and the test models seem to fit most magnums. The only one that had complications, i believe was crashed because the pipe was all chewed up and the arm was bent.

The final version is much more professional looking and entirely made of stainless steel and aluminum, with plated grade 5 and grade 8 fasteners. I dont have a picture handy, but there will be one up on treatland when they get them in.

Honda hobbit variator 'notching'

2010-06-17T11:39:00.003-05:00

I started making hobbit weights a few years ago for friends and such, because there is really nothing on the aftermarket, and the stock weights are hard steel, which is tough to modify, and the chincy little plastic nubs on them fall off. I started with a few different metals and ended up using a very hard acetal polymer.

I have since learned other moped wizard guru types have been doing this much longer than i have, and came to the same conclusions. I've sold a few through Treatland now, of my best design and manufacturing methods, and there have been some complaints. One of the first test sets i made, had the same problem. The weight pushes out too far and gets pinched, with the sharp steel outer plate digging into the plastic and jamming it in fully variated position. Some R&D confirmed this was due to people improperly 'notching' their variators, so I made a note to doccument it the next time i did it. Peter's Blog has a ton of great info on hopping up Hobbits, including info on variator notching. You should read all of that first, but in how it directly relates to 'Moped Factory' Slick Rick Rollers, I would like to add a bit of detail.

The very important first step in the process is carefully measuring a line around the variator 10 mm from the outside edge. I've done this with a caliper, but if you dont have one a wrench might work well. the exact number isn't super precise (+/- .2 maybe) but making sure its even will keep things balanced and make sure it variates precisely.

From Hobbit Vario Notch

Tape off the line so you can see it and make sure its dead-on. Then get your dremel cut-off wheel out and start cutting just above the taped edge, along where the roller 'track' goes through.

From Hobbit Vario Notch

Next, cut the rest of the window out, along the edges of the roller 'track'. I use the hacksaw because its way faster than the stupid dremel wheels, but maybe you're turbo lazy or something. Either way, cut that out of there.

From Hobbit Vario Notch

You will probably be left with a little material in the corners holding it in, a quick tap tap taparooo with the hammer will bust those chunks out.
Before:

From Hobbit Vario Notch

After:

From Hobbit Vario Notch

This is what it should look like from the inside. Note the fact that the cut edge sticks above the top of the roller track by about 3 mm. This is about the thickness of the cut area... coincidence? i think not!

From Hobbit Vario Notch

Now you just take your grinding bit and extend the ramp through the wall of the variator.

From Hobbit Vario Notch

The key is that you aren't grinding down the original ramp at all, just extending it. What you dont want to do is cut off flush with the top edge of the ramp, and then grind it down, you are changing the clearance between the two ramp surfaces, and now the rollers dont fit. Maybe i'll do a diagram of this later.

When you're finished it should look like this: (or maybe even prettier, if you want to go nuts with fine bits... not that important)

From Hobbit Vario Notch

The key is first and foremost making sure everything is exactly symmetrical with respect to the 3 roller tracks.

For those of you who already screwed up your variators, i'll be shipping out some 'oversized' rollers as soon as i can test them. Hopefully we can save the variators.

Test Dummies needed!

2010-06-09T12:05:00.002-05:00

Yeah, finally came up with a nifty solution to the 'Magnum- maxi- exhaust bracket' issue... If you're rocking a magnum and want to try out my new bracket thinger, shoot me an email.

I'm looking for people who will actually put miles on these things, preferrably with estoril's (like heavy pipes) but its more important they get beat on.

Hopefully this will prevent the untimely end of thousands of poor cylinders from broken studs/air leaks/warping... etc.

Spring time- so busy now!

2010-05-07T10:32:00.002-05:00

It sucks I haven't been able to update this in awhile, but sadly, most of what I'm working on falls under the umbrella of semi-classified. I'm back at my old job doing product testing at MSOE, so my free time has completely disappeared, I'm spending a lot of time doing some repair work that has been haunting me all winter, we're getting ready to move, so i'm packing up the shop and getting rid of junk, and most importantly I'm finally getting more parts off the ground and into production. All my cash and time have been tied up with product testing and development lately, but it should start paying off.

If you're waiting on machine work, I'm sorry, things are crazy busy right now, and the heads, kits, etc. are on the back burner while i try to get some products developed. Its amazing how much time and effort goes into producing something from an idea, to prototyping, testing, refinement, production, etc etc. I'm committed to producing the finest quality, made-in-america high performance moped parts, and its very time consuming, but hang in there folks. Some really great stuff is on its way.

Cylinder compression ratio in two stroke engines

2010-02-25T19:51:00.002-06:00

I wrote this post a few weeks back, but its currently about 2 pages and only halfway done. Even i dont want to read it, so i'll try to condense the knowledge and answer most of the questions i've been getting lately about combustion dynamics and compression, without boring the heck out of everyone.

Despite the fact that it contains no valves, and could basically be replaced with a flat slab of aluminum, the cylinder head in a two stroke engine has had an incredible amount of research done on it. The head geometry controls of the major factors influencing efficiency (power) of the engine: combustion pressure, and combustion geometry. The burning of fuel and air in the cylinder is basically a very fast chemical reaction. The laws governing speed of a reaction, imply a faster and more thorough burning of the fuel + air in the head, with a) more air velocity and b) more pressure=temperature=decrease in volume.

Quite simply put, the compression ratio creates a higher pressure in the cylinder when the spark plug fires, causing the flame to 'explode' with a lot more force, pushing down on the piston. This creates higher torque because of more force pushing on piston, but also requires more force to push the piston back up and compress the fuel air mix.

We calculate CR by taking the total volume (displacement plus head) and dividing that by the head volume alone. For a 70cc kit with a 7 cc head (stock 50cc) + gaskets ( 1-2 cc) it works out like (70+8)/8= 9.75:1.

PSI can be an indicator of compression ratio, but requires much tricker math to actually figure out CR. Other factors like ring sealing, port dimensions, pipes, intakes, etc, effect the PSI reading.

The 'squish band' affects the 'v' or velocity part of the equation. Air moving quickly has more energy and explodes faster. Imagine having a bowl of vinegar and dumping in baking soda. If you stir the heck out of it, it will fizz up much more violently. That is what is happening as the piston approaches the squish band. The quick decrease in volume will blast all the gasses into the hemispherical chamber around the spark plug at the same time, the violence of moving air speeds the reaction. Jennings and Bell reccomend the 40% of area- 7 deg taper method of sizing a squish band.

Because of the 'faster' flame in a high compression setup, ignition timing will have to be retarded. The ignition triggers and begins igniting the fumes before top dead center, to account for the time it takes to burn the air. When the everything burns faster, the max intensity of the explosion is at the wrong time and pushes the piston down as it comes up (knocking or pinging). This is exacerbated by a pipe, (or supercharger) which increases the pressure in the cylinder.

Sometimes the compression is just too high, the fuel ignightes without any spark, this is also problematic. Going to a higher octane fuel (only necessary in this condiditon) will allow you to continue to run the higher CR and pipe, otherwise you have to drop CR or go to a different pipe.

The 2 stroke gets more complicated also, because there is a huge hole (exhaust port) in the side of the cylinder. So even though on paper the compression ratio for identical 70cc cylinders, with different exhaust timings, will be the same, the holes in the side, and efficiency of exhaust porting will make their actual combustion pressure drastically different.

Finally, what are you looking for with your bike? The mods that mostly effect the final combustion pressure are: More aggressive intake porting= higher compression, more aggressive exhaust porting = lower compression, more radical pipe= higher compression at high rpm's when pipe hits.

If you switch to a higher compression head, and think you are detonating (sounds like rocks rattling in a can... and isn't your crankshaft) try to retard your timing a bit, see if your power improves. Some kits require so many base gaskets to clear a stock head, or small HC, that by the time all that gets put on there they actually have crummy compression, or a lack of bottom end from having all the ports shifted up. When the compression comes back, a bike that was tuned for different setup, can get thrown off. The detonating sound will be nastiest when you are really cramming on the pipe hard. If the timing doesn't fix it, and you're jetted correctly, and running premium gas and synthetic oil, then try putting in more head gaskets to drop compression a bit.

The cylinders that i've already made a lot of heads for (DR hobbit, MK65, and Polini) the compression ratios are just about figured out, but there is a lot of improvement for specific setups. Knowing what to look for makes it a lot easier to fine tune compression with head gaskets, and play with squishin' dynamics.

Mid-winter update

2010-02-19T10:09:00.002-06:00

As indicated by my previous post, i've been busy as heck. I'm trying to get a bunch of projects finished up over my 'quarter break' coming up at the end of the month here, because next quarter i'm headed back to MSOE more-fuller-time with 2 or 3 classes, and it looks like i'm headed back to my other day job too, so my moped time will be shut down for about 3 months.
I've got three major projects I'd like to get into 'production' state by then, so I can sit back and coast, but its put my personal bikes on hold. I figured, in the spirit of Terry Dean's helming of MotoMatic Blog, i'd cruise around the shop today with a camera and take some teaser photos of what i've been up to.

Vespa cylinders!

100SL2 yamaha project, for a customer, pretty rad bike

Ewwww... four stroke... my CL100 racebike for the Lake Erie Loop this spring. thats got a big 'in progress' sticker on it.

What's this all about?

Exiting things to come..

Busy

2010-02-16T09:40:00.001-06:00

Holy cow, this blog is going down in flames. I'm sorry, i've been too busy to post, but there are a lot of fancy things in the works. Sometimes it seems like the amount of real mopeds v. internet mopeds is inversely proportional.

Ciao FAIL

2010-01-26T08:13:00.002-06:00

On wednesday, i was bored, and still frustrated with not having fixed the leakage issue on the ciao, so Alex, Joel, Jimmy and I tore it apart again (I can get the whole engine out in about 7 minutes now, most of that is removing the pipe) And I was finally able to figure out what was going on. In addition to the Decomp valve still leaking quite a bit, It appeared that when I used the face mill on the cylinder, It cut unevenly where it caught on the edge of the broken off fin. I should have broken or ground that fin off to start with, but you live and learn, eh.

Back in the machine shop, I took the cylinder and lined it up in the lathe, clamping the cylinder skirt. I was in a bit of a hurry to finish it up, and forgot my rule about doing this sort of thing... you have to run a piston inside the skirt or it will break the skirt off. I just had to take a few .001's off, so i wasn't too concerned, but when i started up the mill, some boner had left the feed engaged and right away the tool ground into the face of the cylinder and did this:

What a buzzkill.

I also went ahead and took the head down a couple .001's, which was probably a bad idea because now the extra tall piston i made is hitting, so i'll have to machine that stupid thing down again.

Yeesh, look at that nasty decomp, no wonder it was leaking, carbon and gunk all over...

Oh well, thats mopeds, should have left well enough alone when I had the chance. It looks like the cylinder will be fine with the skirt broken off, but if it eats it, I'm on the lookout for a new stock vespa cylinder. Anybody got one they'd like to get rid of? I've got a parts grande lined up, but i'm pretty sure thats a 10mm pin bike, so i'd rather not back track and rebuild another whole engine.

The good news is, break-in appears to be going well. I was concerned about re-using the old rings, but i cleaned them up with a little sand paper, and re-honed, and it looks like they are sealing really well. Given the wierd compression issues, i was worried they hadn't sealed, but this pic says it all:

The transfers also seem to be pretty well matched, the burn pattern on the piston is a little bit dark, but i'm 99% sure thats because of the wicked air leak causing things to run a bit hot.

You can see on the piston the hot spot from the decomp valve leaking (also perhaps because of the wierd head shape around the decomp) and there is a big black mark where the head wasn't sealing that well. Hopefully cleaning the decomp again and fixing the sealing issue will take care of my shitty low-end and maybe even 'fix' the misfire situation.

Mysteries of the universe. of mopeds.

2010-01-14T13:10:00.003-06:00

Recently I discovered the library.

Rediscovered, is more like it really, I used to spend a lot of time in Eau Claire's LE Phillips Memorial Library reading and perusing all sorts of interesting things, but since coming to MSOE and signing my life over to the forces of homework, lab reports, and other such nonsense, I haven't really had time to waste on fiction. My dynamometer research got me back in the MSOE library where I found the amazing and mysterious TJ section. Titles like 'The design and development of 2-stroke engines' have completely rocked my world and dominated the last few weeks with knowledge I had, until lately, just grasped at.

In the upcoming weeks, I'll be spending as much free time as i can spare reading and distilling all this crazy knowledge, for you, my lovely readers. I just had the bomb of knowledge dropped on me in a big way, not to mention a lot of orders for machine work, and some interest in some of my other lesser-discussed projects, so it might take me awhile to dig out, but trust me, it will be well worth it.

Also, in the world of the ciao... massive head leakage, i think it has a lot to do with the decomp valve which i suspected was leaky-weeky, top speed so far has been a shy over 42, but low end is miserable, and compression is very low. I'll have this written up also as i get a 'round tuit'

Moped tuner/machinist for hire.

2010-01-08T13:00:00.003-06:00

After a few recent conversations, It has occurred to me that I'm not the best self-promoter or businessman. Its apparently unclear here and other places I post my knowledge, that I do moped work for-hire. I spent the summer doing repair work trying to pay the bills, and since I'm still under-employed, I've got a lot of time to hang out in the workshop and make things faster.

My standard shop rate is $30/hr, for just about anything. Fabrication, welding, custom parts, adapters, manifolds, exhausts, if you've read the blog you know what I can do.

In addition to that, some services I commonly perform have flat-rate pricing:

Cylinder head milling: $25/ on-center spark plugs, $35/ off center spark plugs, $30/ Garelli and Minarelli heads with recessed sealing faces. All heads are custom machined for a specific bore and compression ratio, with 2-angle squish band.

From Machined Heads

Stock-cylinder porting: $50, you specify performance characteristics, I compute ideal port map. Jobs requiring additional machining extra.

Dellorto SHA or Bing carbureator boring, up to 7/8" (15.8mm): $20, plus any time spent cleaning/disassembling carb. This is performed to a mirror finish with a boring reamer, I will also remove and modify dellorto emulsion tubes.

Case-matching: $40 + gaskets. Shown is metrakit E50 with additional transfer porting.

From Metrakit Nate B

My gmail address works well for contacting me. I turn stuff around pretty quick, usually a week or less, but it depends on how busy I am. Email and discuss things with me, everything is custom, so Its my priority that its done just right for your build.

Super Stock Ciao

2009-12-22T11:18:00.009-06:00

The lowly Vespa Ciao is one of the most elegantly designed motor vehicles ever produced. Truly the 'volkswagen beetle' of mopeds, its simple, rugged, compact, and designed for cheap mass production. Its no wonder the tuning scene in Europe has gone completely bonkers for these bikes. The parts, knowledge, and resources available for these dwarfs even the mighty puch. Being knocked-off in India doesn't hurt either, making this the most produced, cheapest, and simplest moped powerplant ever.

Ever since I picked up this low-mile rigid Ciao, I knew it was a vehicle with massive potential. TreatsHQ declared 2008 the year of the Ciao with a flood of vespa parts, and I was itching, but other projects took center stage, and it got shipped all over Wisconsin as my beat-around loaner bike. Two years came and went until about a month ago when I decided to set it up for my girlfriend, because what's better than pretty girls on Ciaos? Pretty girls on ridiculously fast Ciaos! (especially when they are stock and embarassing kitted bikes)

The Ciao's massive potential lies in its unique induction system. Rotary-valve induction is different from piston-port and reed-valve induction, in that the opening and closing of the intake valve is controlled by a mechanical valve, usually a disc on the end of the crankshaft, that opens and closes with the rotation of the engine. The rotary valve offers the low flow-resistance of a piston port, with the asymmetrical timing of the reed valve, for a 'best of both worlds' situation. The main drawback to rotary valve induction is the extra cost of the mechanical hardware which forms a tight seal, and extra complexity. Vespa engineers, however, solved this problem by incorporating a recessed area into the crankshaft web, and placing the port on the back of the crankcase where it would be covered and uncovered by the rotating crank web. Genius!

Seeing as this is the only moped made with this style of induction (aside from a few rare Kriedler models) I wanted to see what could be done in the way of unleashing the potential of the rotary valve. Rather than piston ports which just offer two dimensions of tuning (duration and area- time/area) and reed valves which are pretty boring (bigger=faster, yawn!) the rotary valve allows for tuning of duration, advance, area, and in the specific case of the vespa there is a lot of room for improvement. I started the tuning process by researching and studying the rotary valve system itself, and based the entire performance build around the idea that tuning for certain intake characteristics could yield high torque across a wide powerband, with maximum power in the mid-upper mid range. Two years gave me a lot of time to study and think about the improvements I wanted to make, and my research had already yielded a pretty conclusive game plan before I removed the first screw.

Valve Modifications:
Starting with the rotary valve, the geometries of the parts themselves can be improved for flow, specific opening and closing characterisitcs, etc. Looking at the assembly in 3-d, the passage of air from the carb inlet to the cylinder is hampered at any number of places, most likely due to manufacturing considerations. Right away the inlet 'manifold' nipple that the carb clamps onto is much too small to flow enough air. The rotary valve is very efficient, and capable of extremely high intake velocities, so the carbureation can remain relatively conservative, but there is no reason not to maximize the size of the intake tract. The largest I could bore the front half of the Dellorto SHA 12:10 carb out to was close to 14 mm. To maintain the integrity of the nipple inlet, i went to a more conservative 13-something for the nipple, and to match, the back-half of the carb. This was reamed far enough in, that the rest of the porting in the intake port could be smoothed for minimal flow disturbance.

The 'pencil grinder' which is a tiny little pneumatic 1/8" shaft grinder I bought at harbor freight, is invaluable for this stuff. I could actually stick the whole grinder right in the intake hole for the finish work. I left things a little rough because I really dont care that much about making it look good. A slight bit of surface roughness can actually improve flow characteristics if you are dealing with a convoluted shape, but to be honest, I'm just too lazy for all that tiny grinder bit junk. As you can see, I've opened the port up just about as big as i can safely go. The edges are round, because anytime you flow through a square tube, you basically have no flow in the corners anyhow, and this will make the transition easier and prevent any weird eddy-current crap. The primary concern is not breaking the seal made by the crankshaft web on the ground smooth surface around the port. Opening it up 'all the way' like this is only going to change your intake timing by a matter of a couple degrees and this engine is already absurdly conservative in porting.

Because the crankshaft serves as the rotary valve, opening and closing this port, the modifications made to it, directly translate into the modifications made to the port timing in the cycle. To calculate this, in degrees, just measure the diameter, dummy. I used a paper strip wrapped around the crank web, then i double-checked using the diameter, because the paper couldn't be tight or it would shortcut the recessed area of the crank web. Simple geometry will get you into radians of port timing, then degrees if you prefer. I'm not going to share all this, because I think this might be a competitive bike in stock cylinder racing, and I want a leg up on y'all, but if you really want to copy me you can probably figure it out from the picture. I also added some 'flow improvements' to the open area, sortof like knife-edging but in multiple dimensions.

Man grinding on that hardened steel is a real pain-in-the-butt. I still have slivers all up in my fingers. Brutal. The results are well worth it however, the modifications to the intake tract like this can easily out-flow a smallish 4-petal reed. Just think about how much flow area there is while this port is open! Compare that to four little slits 1/8 by 1/2 inches. Not to mention the fact that no energy of the incoming air is being lost opening the valve. We're talking about serious flow here, from a 13mm carb. Exciting!

To finish everything up, I ground out the transfer ports to match the modifications to the cylinder (which we'll talk about later) and to ensure smooth flow between the back of the crank-case and the transfer ports. Its hard to imagine how this all works in three-dimentional space, but I think I was able to clean everything up for a small improvement. I ported the case about as big as I felt comfortable, so if this engine ever does end up with a kit, it wont have to be rebuilt.

Disassembling and reassembling these cases is the nicest piece of cake in the entire moped tuning world. We're talking easier-than-legos easy. Heated bearings, dropped them on, heated cases, plopped it all together with a nice brown-paper-bag gasket and a few dabs of sealant. I splurged for the nicer bearings and seals from my friends at Allied Bearing(still cheaper than the moped shops) because I have a feeling this engine will have the ever-loving piss revved out of it, and I want it to be reliable for many years of blasting.

Cylinder Porting

To say the stock porting is restrictive is an understatement. I took a port tracing to start with, and was very confused by the results. The port map i traced showed the bottom of the exhaust port was 46 mm from the deck. A lot of very slow stock bikes (cough, Batavus, cough) have a ridiculously high deck height, making the piston come a few mm short of the deck at TDC. This drops the compression dramatically and gives you that nice speed restriction Iowa tuners and 'Scared Mommy' magazine are always raving about without having to make pesky tooling changes. I figured this is what was going on, and the wear pattern from the rings seemed to agree, coming well short of the top, so I proceeded to calculate my new port map assuming the bottom of the exhaust was BDC. Once I got everything together, however, I realized the real reason for the discrepancy was due to the piston coming up and covering 3 mm of the exhaust port at BDC.

This is huge

For 3 mm of the already tiny exhaust port to be covered at BDC is shocking to say the least. Correcting this massive error alone could account for an additional 5-10 mph on a stock bike. Its the same thing as raising a stock exhaust port 3 mm, not to mention the transfer ports, which are level with the exhaust on the bottom. To correct this error, I machined a whole 3.25mm off the top of the stock piston, along the edges, leaving more material in the top of the crown to effectively create a 'squish band' between the stock head and the modified piston.
This will drop the edge of the piston to the proper placement for the exhaust port timing, but will cause the piston to rest a full 4 mm below the deck height. I solved this problem with an iron fist. More accurately, the facing mill, which I have now nicknamed the 'iron fist' as it has proven itself to be an invaluable and dangerously aggressive tool for dealing with these sorts of things.
As you can see, the casting wasn't machined on center, but the milling was done true to the cylinder base face, so it should be accurate, not that it really matters all that much for this. Four millimeters is quite a bit, and what you see left of the top fin, is thin enough to slice tomatoes... which reminds me of an infomercial.

Once the cylinder and piston agreed with my theoretical port map, I did a little math and came up with a port map to highlight the strengths of this little machine. Since this is all for my girlfriend to have a nice, cute, reliable bike she can ride with the gang, I didn't want to make it too crazy, but it would have to keep up with the rest of the Cranks at 35-40 mph. The Ciao is so light, and geared so low, that torque isn't as critical as mid to top end power, plus the Tecno Circuit is a pretty torquey pipe. I also have a lot of faith in the stock single-speed dry clutch. Its simple and easy to get/make parts for, so I figure I can sacrifice some low end if I lighten/tighten up that clutch. The rotary valve was designed, along with the pipe, and the cylinder, to start pulling hard around 2-3k rpm, and hang on up to 8-9k. I went pretty huge with the exhaust and transfers, because I know that pipe will keep the low end manageable, and I wanted to have a little bit of power on the top end when the pipe is starting to poop out. I'll probably keep stock gearing for daily riding, but the plain ol' pulley makes it really easy for me to alter the 'gearing' with a short trip to the machine shop, so I might play with that a bit depending on what the GF likes.

The transfers on this engine leave a lot to be desired, and present a serious challenge for the tuner, because there just isn't any room around them to open them up conventionally. Everything has to stay symmetrical for proper scavenging, and that means getting into the two interfering studs next to the exhaust and the one transfer. To lay things out, the studs were drawn into the port map, and I started measuring. The exhaust port is off-center in relation to the transfers. For a moderate build, it could be widened 4 mm on one side (away from the stud, thank god) and probably make 90% of the performance gain my build is going to see. To push it a bit farther, I went even bigger with the exhaust, and bigger with the transfers, shifting them all away from the offending stud near the exhaust. The Transfers couldn't go out much, but they had a few mm to go in, by removing the absurdly thick cylinder skirt and making them 'finger' or fully open ports. I like to be precise about these things, so I took the cylinder into the machine shop and roughed out the ports. I also added a 3rd transfer 'boost' port in between the two gudgeon pins opposite the exhaust. This is directly adjacent to the third stud, so it couldn't be very deep away from the piston, but the boost port doesn't need to be very large to have a huge impact directing and energizing the air out the exhaust port. This should really liven up the 5k-7k rpm range where the pipe is starting to come off its powerband, and give a lot better torque on the bottom before the pipe is hitting. This is the cylinder back from the machine shop, rough, but the important stuff is all there.

The exhaust nipple was also reamed out as large as I felt I could go before compromising the integrity of the metal. I'm kindof touchy about exhausts, because of bad experiences with my Sachs, and dont like to take chances. At this point I still didnt have the pipe so I couldn't match them, but it turned out to be very close.

Once things were roughed out in the machine shop, it was grinder time. A lot of it. Probably about 5 hours total behind the grinder cleaning up the transfers, booster, and cases to make sure everything matches.

Still pretty rough

Getting a lot better

Finished.. with a custom-made base gasket, felt rubber for maximum sealage.

Whew, thank god for photo montage, that would have taken all day

After finishing up the cylinder, and cleaning everything up really thoroughly, the head was bolted back on and i did a quick compression test. I didn't take any photos of the embarassment, but I think my face mill left things a bit too rough, because I had to use a modified puch aluminum gasket and a tiny bit of goop to hold it in place. Ugh, i hate gasket goop, oh well, things seal great now. Torquing those 3 7mm nuts is very touchy, if they are just the slightest bit off they are real prone to leaky nonsense. Who uses three studs? Whatever.

Frame and other such necessary junk.
As much as I hate to admit it, moped engines actually have to go into frames at some point to realize their true potential. I guess that part just doesn't interest me much. Once the engine was back together, and the electronics were re-installed, I slapped it back in the bike. The wiring was a mess from a previous owner, but I had to redo most of it anyways because full-rigid wasn't going to cut it for a daily driver. As much as I love the ciao's aesthetics, either springer front or rigid, they are both almost un-rideable on Milwaukee's war-torn roads. After doubling the speed, I didn't feel very good about putting my girlfriend on something even I had trouble controlling, so I started trying to find different forks. I had a pair of maxi, garelli, and hobbit forks laying around, all of which I tried. The Hobbit forks seemed to be the best fit for size, looks, etc, and they have the same threads as the top nut from the garelli forks which uses the same 'outside' bearing as the vespa forks. Bingo. The tube was the perfect length for the ciao, but not big enough to fit the post style handlebars. Blah blah, boring stuff. Wiring, handlebars, brackets for the headlight. Not done here, but you can see it coming together.

Running with the pipe on.

First start went perfectly. Fired on the first kick, jetting was correct for my basement. No funny business. I adjusted the timing a bit, initially I retarded it a bit from stock because of the porting, but after running it a bit, it seems like stock timing works best. The cold streak we've been having has prevented me from getting out and test-running it, but it pulls really hard on the stand... cant wait until I finish my brake dyno. More results and pictures of finished bike to come!

Update:

First ride on the bike was kinda lousy actually. It was on a very cold day at the beginning of January, and the jetting was way too lean, no power whatsoever, and super boggy. I brought it back in and adjusted the timing, which for some reason was way off, possibly didn't press the foot down enough when gapping. I made a quick hi-flow air filter to richen it up.

The finished bike came out pretty clean, I had to make some headlight brackets.

Here it is all done.

I'm really serious about clean engine bays, wire routing, cables, etc.

So, fast forward a couple weeks, the nice weather yesterday was just too much, I finally got out again on the bike and got a chance to wind her out a bit on lincoln memorial drive. The results are sortof dissapointing. Only 43 mph top speed on the flat, but it picks up to 46 on the down hill (a bit too fast for a rigid if you ask me). I think the compression is too low. I never did actually turn down the head, so i might still have to do that. Also the questionable rings I re-used might be weak. Also the warm weather threw my jetting off again, and now its too rich.

I'm really not happy with the low end either, before the pipe hits, it has no power whatsoever. I know I need to tune up the clutch quite a bit, but there should still be more torque than there is. Correct jetting, finer timing adjustments, and some serious clutch tuning will all be conducted as soon as i have some time. Stay posted for more awesome.

Housekeeping

2009-12-20T16:47:00.002-06:00

So the chainsaw article put me over the top, couldn't keep this little chunk of the internet quiet anymore, so I announced to the MA performance tuning forum, that this is what i've been up to for the last month or so.

Thanks a bunch to everyone who has put up supportive comments, and all my new 'followers.' Knowing people are reading this should motivate more frequent and better posts. Check out the new one on port mapping, and check back for the rest of the writeup on the Ciao. Its getting pretty out of control adding additional boost ports and really pushing the limits of that bizarre little motor. Some midwest moped racing is in the works, and even though its at a disadvantage without a variator (i'm not putting one on, either) it should be pretty dangerous with a powerful engine and light weight.

Also, props to 1977 Mopeds who mentioned this on their facebook. Check out their blog and buy some stuff, cheapass!

Port Mapping

2009-12-20T00:17:00.003-06:00

Most of the people who have gotten hooked on mopeds have come into this hobby as their first foray into mechanics. As amateurs, their approach to tuning takes various routes, but sooner or later the inquiring tuner discovers the power of cylinder porting. The port map, or the placement and size of the ports where they contact the face of the cylinder, serves as the 'brain' of the engine, and a little grinding can have tremendous impact on the characteristics of the engine. My first investigation into porting took an artistic approach, borrowing more skills from my jewelry training than my engineering training. Grinding a half millimeter at a time can yield impressive results, and provides excellent practical experience in what affects what, but as the budding tuner's skill and sophistication improve, a higher level of accuracy is necessary to push the ragged edge of performance. Planning a port map and transferring it accurately to the cylinder, so the physical ports come out the same as the theoretical model you designed, is key to pushing a cylinder to its limits.

For this article, I'll be demonstrating the process I use to create and transfer a port map. I'll be using a stock vespa cylinder which i'm planning drastic changes to. I'll have the full write up on this project done in a couple weeks.

Creating the stock (initial) port map:

To modify the porting accurately, its important to start by determining the initial port map. The easiest way to do this is by 'tracing' the ports, the same as you would take a rubbing of a texture or relieved letters. I start by cutting a rectangular piece of paper approximately the size of the internal surface of the cylinder. Apply a piece of masking tape along one of the sides and roll the paper into a tube. When you put it inside the cylinder, make sure the top edge is perfectly aligned with the top of the cylinder and the paper is fitting tight to the cylinder. You want the paper to perfectly mimic the surface of the cylinder wall.

From cylinder blueprint

If you want to secure it in place with a piece of tape reaching up onto the head mating surface, it might help it from sliding around as you trace. You will want the seam to be away from any of the ports. Now take a pencil, and sketch over the edges of the ports.

From cylinder blueprint

Sketch the border of the paper also, to give you an idea of the actual dimensions, then remove the paper.

Now that you have your port map sketch, go along the port edges with pen or pencil and flush them out. Take your calipers and dimension the ports. The bottom edge of the exhaust is typically 'bottom dead center' and is more important than the top edge. Many cylinders, especially on stock bikes, are taller than the stroke of the piston. If this is significant, it might be helpful to measure up from the exhaust port however far your stroke is, and draw a 'top dead center' line. On this vespa, TDC is a full 3 mm below the deck of the cylinder. You can always change the base gasket spacing to adjust the exhaust port to perfectly match the top of the piston at BDC. When you finish up you should have a drawing that looks like this:

From cylinder blueprint

In the case of this vespa, i've marked up the TDC line, the cylinder stud holes which i have to avoid cutting into, and made some notes about deck and stroke.

'The Math'

Now that you know your original port map, you can start to plan the modifications you want. I'm not going to go in depth on this because its a whole different article, or series of articles and there is lots of good info out there already (Jennings, Bell, et al), go to the library, check out a book, and read it.

Once you've calculated your desired port map, take your calipers to the tracing you made and lay out your new 'ideal' port map. You can see on my map where i've laid out the 'horizontal' axis along the bottom, and measured up from the 'BDC' line along the bottom of the exhaust port. In this map, i'm also rotating the porting slightly so i can get more exhaust port in along side that stupid cylinder stud, so you can see where i've laid out a new 'exhaust centerline' and spaced everything off that point. You can also do this all in CAD if you want to take the time to draw it all in cad. Either way you should end up with something like this:

From cylinder blueprint

Now that you've got your port map, take an exacto and cut out the ports. If you're doing 'finger porting' or fully open transfers, you'll want to cut long strips. When its all cut up it will look like this:

From cylinder blueprint

To get the porting traced back into the cylinder now, take your port map, and tape it into the cylinder the same way you did the first time. Alignment again is critical. Align the top edge of the paper with the top of the cylinder, open the tube of paper up tight, and tape it in place. You'll have to either eyeball the centering around the exhaust port, or in my case, the edge of the port near the cylinder stud is going to remain the same so im lining it up with that edge, and level to the bottom edge of the port. Unless you're getting tricky with raising the ports by the base gasket, the bottom edge of the exhaust port is your BDC level. If everything is aligned well and its taped securely in place, the port sizing should work out perfectly.

From cylinder blueprint

Now, we see why we cut the holes out with the exacto. You can either glue the paper in place and use that as your guide, or, simply trace the edges of the paper with a marker. Paint marker is the best, also those 'Pilot gold sparkle' markers work great, because they stick to metal better and are opaque and easy to see with a fine point.

From cylinder blueprint

Now you can pull out the paper and grind away what you've drawn in. The sizes you calculated come out perfectly, and your porting should do what you want.

good luck!

What is this doing here?

2009-12-16T08:47:00.006-06:00

Maybe its the Wisconsin in me, or the farm boy passed down from my father, but I've always had a soft spot in my heart for the mighty chainsaw. Of all power equipment, it has the most potential to reduce human work, its a two-stroke, and up until retards started buying them at Home Cheapo, they were almost exclusively made in Wisconsin. What more can you ask? Oh you want it to be the most hated entity by hundreds of thousands of smelly hippies and an ideal zombie killing weapon (when attached to your arm). Done.

From Chainsaw

Ok, I admit I have a bit of an addiction to 2 stroke...

Yesterday, Instead of doing something productive relating to homework, getting a job, or the Ciao, I dorked around with this beautiful old chainsaw that was languishing in my buddy's garage. At first i was just going to get it running so i could clean up some brush around my yard, but then he said 'heck if you get it running you can keep it' (I love it when people say that).

So, i tore the whole thing down, cleaned it up, and did a little performance tuning. Once I realized how beautifully this was made, I couldn't resist. A perfect example of 'they dont make 'em like they used to' this thing is entirely aluminum and weighs next to nothing. Its probably 30 or 40 cc's, with a MASSIVE 15mm walboro carb. The intake and exhaust ports are huge, and it has fully open 4-port transfers. It even has some sort of wierd side porting in the piston that looks like its supposed to boost the transfers. It would definitely explain why such a tiny little saw has such a massive blade on it.

From Chainsaw

Talk about some serious slasher-movie shit.

It wasn't running because the points (i cant think of the last time i've worked on lawn equipment with points) were completely out of adjustment. I dont know what they are supposed to be, but I eyeballed it, and put it together enough to start the engine outside of the housing with starter fluid. When it caught it just about tore my arm off... close one. Sure enough started on the first pull.

I ported it with the engine completely together.. because who cares really. After porting the cylinder was hosed out really thoroughly with carb cleaner and compressed air. I went about 1.5 mm higher on the exhaust... width was maxed out at at least 70% of bore. The intake i dropped about 1mm and smoothed out the intake manifold transition. The intake and exhaust were on the sides of the engine, and they were already massive. The stock air filter, as seen under that beautifully styled black grille, was made out of what looked like arts'n'crafts-style felt. I replaced that with a 'hi-flow' chunk of air conditioner filter for a little extra boost (mostly because i was too lazy to clean the old one.)

After putting it all back together, I realized someone had tried to adjust the Wally Walboro carb and failed miserably. The high idle screw was all the way in, the low idle screw was mostly out, and it wouldn't run at all. I put them in the ballpark of 1.5 turns out and got it running on starter fluid, and dialed it in. Holy Crap this thing rips. Definitely one of the scariest chainsaws i've ever used. It doesn't have the smooth balance of say, a Husqvarna, but it revs way higher than it should now, and the inertia of that huge blade just about yanks it out of yer hands. I'm going to dig around for some hockey tape today and try to tape up the handlebars for a bit more grip and to give it that 'freddy krueger' look. Maybe while i'm at it I'll fashion some sort of crude prosthesis for my arm.

Zombie Apocalypse here i come! Does anyone know where i can find a mini circuit pipe for cheap? Maybe one of those Puegeot Faco chambers on treats? How rude would that look hanging off the bottom?

UPDATE:Just got a chance to slice up some brush in the neighbor's yard. Holy damn, this thing is sick. Not quite as fast as my Poulan Pro model back home, but definitely more torque. A smaller blade would probably run faster, but the blade thats on it is really nice with a roller tip and a brand new chain. The autolube isnt working, but i'm sure its just a bad seal or sawdust in the guts.

Update Part 2: I was going to go buy bearings right now, but my stupid landlord parked me in again. Instead I went all Bob the Builder (can we fix it, yes we can! for those of you who don't have 5 year old cousins) on this shit. Turns out I was removing the engine all wrong. When done correctly, you can pull the entire engine out of this thing by removing 6 screws. Yes thats right, the entire engine can be torn down and put back together with a 5/8" socket and a flathead screwdriver. Awesome. Four more screws removed the oil tank, which bolts to the bottom of the engine. This reminded me how much i hate it when people goober RTV all over everything. Someone else had this apart at one point in time, and apparently they felt they knew more about the design of the saw than the engineer who originally designed it (a pretty smart guy apparently, as he figured out how to get the engine in and out with 6 FUCKING SCREWS!) Anyhow, they gobbed RTV all over the mating surface, which happens to go around the passage way that the oil runs through. There was RTV all up in the oil injector hole. Thank god whoever did this was also too dumb to tune a wally carb or else the clutch, roller bar, and chain would probably all have been shot.

In other news, i think the next time i get an extra $25 chillin in my pay pal i'm gonna put one of these on it.

Tiny Puegeot Pipe That looks about the right size for the engine i'm working with. Silencers? Silencers? We dont need no stinkin' silencers.

Black Majik- part 1

2009-12-11T23:29:00.006-06:00

Annie.

From Black Magic motor

One name is enough to say for the early Cranks who knew her as the first truly fast moped in Milwaukee. A faded orange (red?) swinger 2, she had over 7000 miles put on her in the first two years of the Cranks by yours truly. A faultlessly reliable, charismatic, and brash mount, she carried my ass to many rallies, rides, and how-the-hell-did-i-get-home benders. When the countershaft bearings finally went out in the spring of 2008, I shelved her in favor of my newly finished Sachs (Sally) and made great plans for a triumphant return to glory, including disc brakes, magnum x forks, and a case-reed-inducted 50cc powerplant.

Things change, as they always do, and other projects took precedent. The cases got machined for reeds, but the cylinder was never finished, and the decrepit frame gave of itself many small parts as it languished in the fortress. A few months ago I pulled out the original engine with the siezed countershaft, in the intention of hosting a class on E-50 rebuilding. I happened to have an extra 70 TCCD laying around, and decided it was time to finally see what the little piston port could do. The more i thought about it, the more I liked the idea. Annie was never a prissy race bitch with fussy adjustments, picky about fuel, or hard to start. Annie was a creature of the streets, a lean, sinewy, back alley blaster with a heart of cold forged steel. Eager to tear out into the night on missions of ill-intent at a moment's notice.

And so, black majik was born.

When the first build was conceived, 50cc reed inducted, I bought a fully stuffed DMP crank (like, the week they came on the market before people started 'splodin' them) and did some lightening on the countershaft gear. Quite a bit of lightening actually, took about a third of the total mass and about 60% of the rotating mass out of the thing on a lathe.

From Black Magic motor

I got the crank and countershaft ready to go with nice new bearings and seals from my friends at Allied Bearing (they smoke in the office still, awesome dudes) and started looking at the transfer porting.

The TCCD 70 has pretty gnarly transfers stock, but they just weren't good enough for me. The thing that really chapped my balls was there were a couple areas where the ports came way too close to the edges of the case, and vise versa with the case ports, just about sticking out in the other corners of the cylinder. My first thought was to keep it conservative, but then i thought, what the hell, free kit, extra engine... lets get radical.

I made a plexiglass plate that would fit around the skirt and bolt into the four cylinder stud holes. Then I mounted it all down to a 2x6 using wood screws through the stud holes. I mixed up some real nasty pro style epoxy shit and built it up around the transfers. Then i clamped down the plate to leave a smooth finish level with the deck. I repeated the same process for the cases and ended up with this.

From Black Magic motor

Thats after a little bit more porting, not quite finished. A few more hours with a grinder opened up the intake, transfers, and exhaust port. The exhaust was about as big as it could be, the intake got opened up a fair bit.

From Black Magic motor

The piston was modified, but after putting it together i think i went too far. The boost port holes go into the intake port at BDC. I know this will cause it to spit out the carb something fierce, but i'm not sure if it will still run well and be acceptable or if its too far to have any bottom end. We'll see once i get her fired up.

From Black Magic motor

The ignition is installed and ready for a CDI box. Thanks to Matt from Florida, I've gotten a lot of really good advice on my ignition options. What i have here is a early-model A55 ignition coil. It uses a thyristor box like the A35's but it has the smaller diameter with the radial coils like an A55. An ignition with a pickup would be nice because i could run all sorts of fancy CR and YZ 80 ignition boxes with crazy curves and stuff, but this will work for now. It sounds like the A35 box has pretty good curves in it from the factory, so i'll be trying to snag one of those. The mounting simplicity is amazing, just bolt on and go. All the holes lined up perfectly and the flywheel dropped right on in the right place. Awesome. Hopefully the timing works out to be the same, but that is all determined by the box. It sounds like the A35 box will run on this engine no problem, which means the timing is in the same location as a CDI 35 which is the same location as a points 35 which can swap with a puch points stator 100%, so it should all just... uh... work?

From Black Magic motor

In the background you can see the remains of a honda Z motor CDI unit that i bought a few years ago when I was playing around with 12v lights on my Sachs. Its got a good pickup, so if all else fails, i'll mod the shit out of a flywheel cover and mount that damn thing somehow, but it would be way messier than the beautifully stock-looking system i have now. The cool thing about all these 'pickup' type CDI's is they are totally interchangeable with a little hackin'. I'll probably end up putting the XR50 inner rotor on my Tomos eventually.. but thats another post.

Finally buttoned up, all i have left to do is trim that stupid starter gear off so i can get the flywheel cover over it. 80W light power here we come!

From Black Magic motor

Santa came early

2009-11-25T08:26:00.002-06:00

Thanks to my exceptional good moped karma, I've recently come into the posession of an A55 stator and flywheel. This is the older one without the tabby for the pickup, but if i'm not mistaken, i can get a 2 wire CDI box (some sort of thyristor setup, i'm sure) that will work from an A35 or pre-2007 A55, or i can try to adapt a pickup and get things working with a RM, or YZ80 CDI box... I'm not sure what i'll do yet, but this is a 100-some dollar piece of the high-rpm puzzle that has just magically fallen into my hands and i'm pretty excited. I'll be headed to the machine shop later today hopefully to trim off the stupid starter ring gear, so i can fit it under the stock e-50 magneto cover.

Just goes to show you, never burn your bridges.

Also, lots of new pics up, an article on refreshing a motobecane, and the long-awaited second part of the timing series are in the works... plus a quick and dirty (literally) piece on rebuilding cup and cone style bearings. Ooh exciting!

PS.. if you're as excited as me about this (doubtful) you can scope the first look at my porting pics... pretty gnarly.

Motobecane L'amour !

2009-11-25T08:24:00.004-06:00

Motobecanes are peculiar little creatures. Definitely the most spirited mopeds I've ever worked on. They can vary 10 mph in top speed from day to day depending on how they feel, and go from starting in one kick to frustrating you to the point of tearing your hair out, over night. While it is important, as with any moped, to maintain positive energy and respect the moped's spiritual soverignty, there are a few modifications which, when done correctly, will greatly increase the chance of him/her starting predictably. When done properly, these improvements will not upset your Motobecane, rather will strengthen your bond and make your moby a happier little animal.

To start with, any venture into moby-land is incomplete without a visit to Mabecane's Mobylette page. The virtual proprietor, MaBecane, is one of the most interesting people involved in mopeds. He loves these bikes like children, and shows an unmatched zeal for historical preservation, caretaking, and helping others keep their mobies running long after it makes sense. Check it out here for tons of info and pictures to get you excited about your build: MaBecanerie Also, grab a manual while your at it. The manual is a poor copy/translation, but the verbiage is really pretty, in french style. Lots of adjectives to fully illustrate the tenderness that is inherent to motobecane repair.

Esti (above) is a good friend and former neighbor of mine, she is a perfect candidate for a moped rider, and since riding some bikes when I moved in underneath her, she's been looking for a 'yellow moped.' Not many bikes came in yellow, but i knew of one brand that did, and a Motobecane was a perfect fit for her classy style. I found this 1976 50v in a friend's storage unit, in pretty good shape, completely covered in black greasy grime. The grease protected the paint and chrome, and whoever had it last managed to avoid bodging much besides the carb, seat, controls, and electrical. The cylinder was tight, had good compression, and all the important stuff was there. This is pretty typical of a 'barn' or garage find moped, so I'll go over the common problem areas and detail the repairs and modifications I made to her bike, so a novice could get her feet wet with a reliable and fast machine as she learns the ropes.

Most barn/garage rescued Mobies will have all the cables frozen on them. For some reason the grey cable they used cracks and rusts out like nobody's business. The motobecane uses knarps on everything, though, so you can pick up a full mountain bike cable pack at your local wal-mart, for $7 and cut all your own cables to fit. If you want to get crazy, and replace everything with OE grey cable, you can talk to my friend Matt Quirk, at Motorwest Motorcycles in milwaukee to get a roll of the grey stuff in much higher quality than Motobecane ever intended.

At the very least you'll need new throttle, front brake, rear brake, and possibly decompression. Choke depends on the carb you use.

Speaking of that carb... Motobecanes are notorious for the Gurtner carb. Many moby fanatics will tell you they can go 50 mph on the stock gurtner (i've seen it..). For someone who wants to eat, sleep and breath french, the gurtner is a perfectly workable unit. For most of us however, its much cheaper and easier in the long run to just swap out to a generic Dellorto SHA. You loose the extra cable of the choke, you get standard replaceable jets, air filters, a bigger throttle, and they are less likely to leak with the rubber-tipped float needle. You can use either the real-deal SHA 13 (vespa style), or the Spaco clone (kinetic), or go to a standard 14 SHA or 14 SHA clone (my favorite). The clones might have some issues with changing jets, but if you're hardcore and used to making weird stuff work, you already have a set of JET DRILLS to fix that. In addition to your fuel system woes, the stock petcock is almost invariably broken or leaky. Quarterkick.com seems to have these in stock more often than the other guys, so give Chad Burke a try first. If they aren't on the website, they might still be in stock.

The Motobecane AV7 (50v, 40t, 7, traveler) comes with either a long bendy intake, or a short stubby intake. The stubby intake is actually too small to easily mount a SHA carb (apparently with a little fin grindage the 13SHA fits), but either way, its much easier to just buy the Malossi SHA intake for av7, which is available dirt cheap from the major moped parts sellers.

I've heard some nightmares about Moby Electrical, in fact the first two mopeds I ever owned were mobies left outside for many years, and were hopeless, the coils were all rusted to hell. For most motobecanes in fairly good condition, the coils, condenser, and points are inside the flywheel and fairly well protected. The problem areas with moby electrical are the questionable connectors, namely the white plug thingy under the floor boards, the coil, and the incredibly awful spark plug wire.

The terminals of concern are the white ones under the floorboards. The prongs in them are very small and flimsy and prone to corrosion between the terminals themselves (easy) or between the terminal and the wire (very hard to diagnose) they also have a nasty habit of popping the terminal itself out of the white plastic housing, making it look connected when it isnt. If they look good, hose some dielectric grease in there and forget it. If they are really shot replace them with soldered or properly crimped on blade terminals.

The NOVI coils, white, strapped to the bottom of the tank, are prone to cracking and rusting inside from what i can tell. The spark plug wire is a proprietary unit with compression style terminals, and an obscure 5mm diameter. I would strongly reccomend buying the 'universal moped coil' that the major moped retailers have for sale. It uses a standard 6mm wire with screw post, seems to deliver an incredibly strong spark, and is all zinc plated and epoxy potted for long life. It grounds through the frame so the coil wire should work fine. Everything should be a very simple plug-and-play situation. You'll need two 5mm bolts to bolt it on. dont forget lock washers or nylock nuts. Set the point gap to stock, clean up the points, and you should be getting a nice fatty spark.

For performance stuff, you probably wont need much if you have the 'fast' 30 mph cylinder. They fly pretty well out of the box. Upper 30's with a 14SHA means everything is solid. If not, your timing, bearings, variator belt, or brakes might be at fault, or you have one of the slower cylinders (or your exhaust is plugged, but this doesn't seem to be much of a problem for moby). The only differences between the two is porting. I wont go into it in detail because there is much better info out there, but lowering the intake about 1mm, widening it 1mm on each side, raising the exhaust about 1.5 mm and widening it about .5 mm on each side with a nice radius up to the top, should get you close to the stock fast cylinder specs. It might be easier to take the engine off if you are going through this much work.

Yep yep, so thats about it. Moby refresher in a nutshell. The first time that thing pops to life, you will understand the beautiful feeling. They whirr, they rattle, they glow, they are strange little beasts, but when properly set up they can be amazingly reliable and a real pleasure to ride for many miles. Once you have your bike running and solid, you may also need to replace the rubber engine mounts (which i'll cover in another post sometime) or do some of the other basic tuneup things such as bearings and brakes, which are similar to the Puch demonstrations i'll post up here soon.

Au Revoir!

Timing Part 1

2009-11-22T04:25:00.003-06:00

Timing Part 1- Theory

Introduction:
Ignition timing is a frequently misunderstood and misinformed topic in the moped community. A basic understanding of the physical principles occurring in the combustion process, and the system by which the spark plug motivates this controlled combustion, will allow the tuner to adjust ignition timing to the optimal point in the combustion cycle for maximum power. This article is the first of two parts, detailing the theoretical role of ignition in the power cycle, and the implications various performance modifications have on optimal ignition timing.

To begin, lets look at the role of the spark in the combustion cycle. The ignition event occurs between the compression and power strokes. After fuel and air has been forced into a small volume and raised to a higher pressure, the spark ignites that volatile mixture and the resultant heat and pressure force the piston down to provide motive force (powahhh!!). This at the outset seems like a fairly simple proposition, but in reality there is quite a bit happening in the few milliseconds during which the piston approaches top dead center, and begins its decent.

Overview:
In reality, considering the spark and combustion of fuel as a finite event (happening all at once), is an oversimplification. The piston is traveling at such a high speed, if you were to slow things down to a comprehensible speed, the movement of the flame itself through the combustible mixture in the cylinder, would seem to happen very slowly. This ‘flame front’ speed is based on the pressure of the mixture of gasses, which is changing as the piston nears top dead center, it is also based on the fuel/air ratio, and the temperature of the gasses in the cylinder.

Going back to the cylinder now, the piston is coming up from bottom dead center, the cylinder is full of air and fuel mixed. As the piston nears the top, the points will close, breaking the flow of current through them, and diverting the electricity to the spark plug. The point at which the points ‘break’ or open, is the point used to determine timing using a timing strobe, a test lamp, or a cigarette paper. There can be a little bit of dwell downstream in the system also, from 1-3 degrees. A hotter plug will spark more readily, also a smaller gap will jump faster, so if you change these, your timing might change incrementally.

When the spark jumps across the electrode gap, the mixture, which by now should be at a very high pressure, will ignite. If the fuel mix is correct, and the piston is still traveling upwards, the flame will burn up the fuel and air mixture in the cylinder just as the piston is passing top dead center (the most powerful combustion will occur when the pressure in the cylinder is highest- e.g. top dead center), and maximum power will be achieved as the pressure from the burning gasses pushes down the piston.

Combustion theory and implications:
Now perhaps it is a bit clearer why ignition timing is so important. If the timing is off by even the slightest fraction of a millimeter, peak power won’t be achieved. This is why many people will say ‘the power is in the points’. In fact there is no power whatsoever ‘in the points’ unless they are set wrong for your particular application. Understanding the various effects modifications can have on the ignition timing, will facilitate better ‘guesstimating’ as to the optimum setting of the points. The key is the relationship between the fuel, exhaust, and temperature conditions and their contribution to flame propagation.

Flame propagation in the cylinder is a relatively simple concept when we go back to thinking of the combustion in super-slow motion. Chemistry tells us that the rate of any chemical reaction is proportionate to the initial energy. In the engine, that energy manifests itself as temperature and pressure. We assume no change in temp. We started with an initial volume of fuel/air mix and compressed it by the compression ratio to get our final pressure. Compression ratio has a huge effect on final pressure, and reaction time- read flame propagation time, but its not the only factor.

The initial amount of fuel/air in the cylinder is called volumetric efficiency, the amount of the cylinder displacement that is filled when the piston closes the exhaust port. A more efficient intake and transfer tract, along with a pipe, or the timing can all change the volumetric efficiency. Anything that increases the VE, will make the flame propagate faster, and will require ignition retard. When a pipe comes ‘on’ the powerband, it is pumping more effectively, and increasing VE. Port timing also can contribute to varying VE at different points in the powerband.

The other major contributor to flame propagation is cylinder bore diameter. For the fuel to all be burned the flame must cross the entire surface of the bore. It might seem small, but going to a larger bore requires more time to burn the fuel.

There is a delicate balance when adding performance parts or modifying your bike. Everything has the potential to change the timing, and we have very little recourse with the simple points magneto system most stock bikes have. The original design is for a relatively constant powerband between 1000-3000 rpm. Wild variations in the efficiency of various parts at various speeds can require dramatically different timings.

Common problems:
Some commonly occurring problems with timing are pretty obvious, but the small, silent loss of power at various speeds that is frequently cited by the ‘power in the points’ crowd, is something that can only be avoided by painstaking tuning. In fact, points magneto systems aren’t nearly accurate or tuneable enough to deliver peak power at all ranges, but usually a happy medium can be found that allows for good performance across a wide powerband.

Should the spark jump too soon, a condition known as detonation occurs. This is frequently referred to as ‘knocking’ or ‘pinging’ and in a highly tuned moped engine sounds a lot like a tin can full of marbles being shook. It is confusing to troubleshoot because of its sibling condition, pre-ignition, which shows up in exactly the same way. Its hard to tell the difference because they both cause the same effect, the noise you are hearing is the fuel/air mixture in the cylinder igniting before the piston reaches the top of its stroke, so the upward movement of the piston is met with a downward explosion.

In detonation conditions, the spark is jumping too soon or the flame is propagating too quickly (same thing, relatively speaking). This is why some bikes with aggressive porting or exhausts require more ignition retard than stock, or some bikes need retarded at higher speeds. As the pipe hits or the ports work more effectively, the amount of air in the cylinder (volumetric efficiency) can increase with a supercharging effect, causing the flame to travel faster throughout the cylinder.

In pre-ignition, the condition is being caused by hot surfaces inside the engine due to the wrong heat range spark plug, high cylinder temps, or too low of octane fuel for the compression. While both conditions result in the same effect, the causes are dramatically different, and the solution is as well. Due to the extreme risk of engine damage these need to be understood and correctly diagnosed.

On the other side of the coin, backfiring and power loss are telltale signs of the timing being too retarded. If the combustion occurs as the piston is already heading back down, it doesn’t take much time at all for the burning gasses to blow right out the exhaust. If this happens, the combustion only acts on the piston for a brief instant, and the piston cant harness the burning fuel. Backfiring can occur in extreme cases where the flames either blow out the exhaust, or even back down into the crankcase when the transfer ports open. Typically in cases where the timing is only very slightly retarded, the bike will have poor or no throttle response, or loose throttle response under load, but maintain it when it is on the kickstand. When there isn’t anything to push, it can rev up, but once load is applied the short amount of time the gasses push on the piston before blowing out the exhaust, isn’t enough to overcome resistance. The transfer ports can even flow backwards or stall depending on the extent of porting or the pipe.

In conclusion..
Timing need not be a mystery, or entirely guess and check. We are just starting to see the types of programmable CDI units that would allow us to dial in perfect timing, but in the meantime, the points magneto systems are perfectly workable, reliable, and offer a very simple, direct type of tuning. Having a good idea going into it about the effects other performance parts can have can facilitate easier tuning, and a better understanding of our bikes.

Crankcase compression: theory and implications

2009-11-19T09:28:00.008-06:00

I originally wrote this for a moped army forum thread located here: http://www.mopedarmy.com/forums/discuss/7/189038/189038/

With the increase of availability of moped parts here in the U.S., we've seen a huge boom in the technical sophistication of domestic tuners. With this availability, everyone seems to be pushing the envelope further, trying to squeeze out every last iota of power from our little machines.

A good example of this is the availability of 'stuffed' cranks. Many of us have purchased them for absurdly cheap through the US moped parts sellers, having only a vague idea of what it really means to 'stuff' a crankcase, why it can produce more power, and what the implications are for the rest of the engine.

Crankcase stuffing is decreasing the volume of the crankcase to improve what is called the 'primary compression ratio'- the compression ratio for the system comprising the bottom of the piston, crankcase, and transfer ports up to the edge of the piston.

Primary compression is defined as Vi/Vf which is:
volume final divided by volume iniitial.
final volume is the displacement volume of the piston plus the volume of the case. initial volume is just the volume of the case.
when doing this for a cylinder, the head volume is relatively small, so we can achieve 11:1 (11/1 = 50cc disp + 5 cc head volume/ 5 cc head vol.) or better. When we do this same thing in the case by either increasing the displacement, or decreasing the crankcase volume (say, by stuffing the crank) we can get better compression ratios...

so what? right? why does changing the compression ratio help us?
having a higher crankcase compression ratio lets us get more air in during the intake phase, and creates higher pressure pushing that air through the transfers.
This is obvious when we go back to high school chemistry and remember PV=T(nr): Pressure times volume equals temperature, if you decrease the volume of an area, the pressure or temperature MUST increase to compensate. In the very short time that the piston is going up and down, we can assume the temp cant change much.
This makes sense for the second part, the transfer pressure. The higher pressure from a smaller final volume will push the air through the transfer ports at a higher velocity, improving scavenging, and transferring more air in the very short time the ports are open. But this only makes sense if we are getting more air in the crankcase in the first place. The displacement of the piston isn't changing, so we cant change how much air gets into the crankcase right? Wrong.

The higher ratio means that when the piston goes up and creates a vaccum in the crankcase, the vaccum is stronger. Even though transfer pressures can be as high as 50 PSI, the intake pressure pushing air through the carb and past your reeds is only 1 bar, because it is being pushed in by the atmosphere. You want to get as close to a perfect vaccuum as possible to get air to transfer as quickly as possible. (This is why piston port engines can blast reeds at the top end, the piston port has much less resistance to flow, but i digress. ) Having a compression ratio of infinity, as in 0 crankcase volume, with no leaks, would create a 'perfect' vaccuum, This would provide 32 PSI across your intake tract from the air filter in. In reality this is impossible, the ratio drops very quickly with increase in volume in the case, and the potential transfer pressure drops from 32 even faster, by PV=T. The time your piston is going up is limited by your RPMs, and the amount of air that can transfer is limited by the pressure, restrictions in the intake, and time. Therefore, if you can make more pressure (by improving the vaccuum in the case) you can get more air in the case on each stroke, which means you get more air into your cylinder, and can burn more fuel.

Current Project Teaser

2009-11-17T12:01:00.002-06:00

I've got four major performance builds right now that are newsworthy:

Sally Balboa
Sachs 505-2BX- Hand shift, manual clutch, long stroke motor from Roald in the Netherlands
80 cc Athena reedvalve kit
Puegeot 103 pipe by Simonini
Mikuni VM18 carb
More time and custom parts than i want to admit...

From Sachs 2bx-80

Annie 'Black Magik' rebuild- at one time a swinger 2
E50
70 tccd
lots of fancy schmansy custom junk.

From Black Magic motor

Tomos sprinter
70 Alukit, 2 petal polini reed block, 22 mm kehin clone...
custom everything, including beefed up bottom end with roller bearing con-rod, caged bearings, mod. clutches
rigid with dropped front end.
homemade hydroformed pipe
needs to be tuned for E85 and needs some sort of CDI.

From Sprinter

And, last but not least, a project for my buddy Dez, the roadBLASTER
Low budget, old school tuning:
porting, reeds, grindin' up shit.

From Projects

For my pictures

2009-11-17T11:47:00.002-06:00

Picasa integrates really well with blogger, through the googles, so i'm using it to host all my pictures. Some stuff will be for sale, some is teaser pics for posts i'll write later, lots of Milwaukee ride photos. Check it out if you're really bored.

From Cranks

The workshop.

2009-11-17T09:54:00.004-06:00

June of 2009, My lovely girlfriend Caitlin, and I signed a lease on an adorable cottage/back house. The place was rough, the rent was cheap, but the basement had a 4-Step egress door and a derelict, cluttered workshop. I wish i had some before pictures, because it was a mess; wood everywhere, no light bulbs, dirt floor, trash from the previous tenant all over. The potential was there however, and over the summer of 2009, I've cleaned out the junk, burned the wood scraps, patched up the dirt floor with other scraps, cleaned up the workbenches, and generally improved the heck out of the place.

Fast forward to November, I'm settled in for the long hard winter with a ventilation blower, air compressor and tools, workbenches all around, 'grinding station', lighting, spray booth, and almost every tool i could need to do top shelf moped repair.

I've been rediscovering some long-dormant writing skills, and now that day-to-day repairs are slowing down for winter, I have more time to work on performance tuning, which should be more interesting to write about.

From Cranks

So, I've decided to start blogging as much of this as possible. I've never done a real good job of documenting all my moped projects, but I think its a good idea to make myself work cleaner (as other people will be seeing it) and share ideas with other tuners in the MA online community.

I'm trying to turn writing into a career at some point in my life, technical or otherwise, so please critique the heck out of my posts. I'll do my best to write them in a clear, concise, professional style, and doccument with good pictures.

As you guys correct me technically and verbally, I hope to improve as a writer and engineer, so Thank You for reading! I'd also like to thank Caitlin, my girlfriend for putting up with all of this garbage, noise, and still letting me use her camera and computer to do this. I'd also like to thank the bloggers i've linked, as they all do a great job and motivate me to push harder and work cleaner.

yay

2009-11-13T00:03:00.000-06:00

its got that new website smell, hopefully i'll do something with this.