Modern Vespa

Here are some better photos of the crank after cleaning it up a bit. Just giving it a closer look before deciding to bin it.

Depends on the cylinder port timing. Best results are when the inlet timing is tuned to match the cylinder timing.

Does the crank look like it could be salvageable with a polish or should I toss it?

Thanks.

That crank is junk. Toss it now! Don't keep it for later. It's junk.

One of those "say it ain't so" moments when you get in deeper than expected. But it's the nature of the beast.

Indeed.

It's not like it was Schroedinger's Crank and only became definitely trash once you looked at it.

Someday, I will describe in detail my theory of sentient machines. Maybe some other time.

It was 50* here with dry roads, so I went for a ride on the Stella.

I swapped the 116 MJ on the 140/be5 combo I was running for a 125 MJ. I really thought the 125 would be the too big jet and make it splutter and run like crap at WOT, but it didn't. The 4 stroking hung in past quarter throttle, but it was really clean at WOT. I think I hit 7k rpm in second gear.

I took it for a short hop on the state highway and easily got it up to 60. I was really pleased as it's been kinda meh. 4th pulls a lot better too. I guess I will have to drill the float bowl now and go bigger on the main.

If there's another chance to get out, find out what MJ jet does make WOT splutter. You are correct the carb will need drilling to over 2mm first or it will never flood. Do it by hand and be sure to see the drill bit at the bottom of the stack.
Ignore what happens at 1/4 throttle until after the MJ is done at WOT.

125 might be the biggest jet I have. I will have to check and order more.

I will get the main right before worrying about 1/4 throttle as you said. Feels like I'm going in the right direction though. It really woke up the top end. I was going up hill when it hit 60. It had more but I had reached the stop light.

Back to the 200…

The only 60mm crank Scooter Mercato
has listed on their website is a cut version. I don't know if Mazz makes an uncut 60mm or if the cut 60mm would work fine.

https://www.scootermercato.com/Scooter-Parts/Crankshaft/190334L

I'm trying to keep things simple, though I do understand the basics of how to measure and calculate and adjust timings with base or head spacers. I found an article on timing basics. It mostly discusses timings based on peak rpm. I know there is a lot more to it, but I'll cross that bridge when I come to it.

I also need to replace the piston. The cylinder will just need a light hone. I'm wondering whether I should go with a GS piston or stick with stock.

I would like to stay close to the simplicity and reliability of the stock 200. I like that it will easily hold 55 without being wound out. It suits my grandmotherly, ride it like you mortgaged it riding style.

If keeping it generally stock, I would go with the uncut 60mm crank. If one day it will have a cylinder kit, then the cut version.
The stock 200 meteor piston is hopeless. Heavy and rings that wear badly and don't seal great. GS piston option if available. If the stock cylinder needs a rebore fit a malossi 210 piston!

I will give Scooter Mercato a call as I don't see an uncut 60mm crank on their site.

SIP has this one, which I think is an uncut version. It's hard to tell:

https://www.sip-scootershop.com/en/product/long-stroke-crankshaft-mazzucchelli_45020000?q=amt166m

SM also has the GS piston in stock. The Malossi 210 piston is a good idea, except I'm not sure how much work it would take to get it to fit with the stock cylinder. The local machinist here would bore the cylinder for $50 insluding chamfering the ports. Still trying to keep it simple though.

I'm really holding off on performance options for the Malossi VR-1 case sitting on my shelf. At some point, I will start spit balling about that engine, but one at a time.

That crank is heavily cut, 138 degrees. Look for one with around 115 degrees if keeping stock forever.

The GS piston and 210 one are expensive. If you need a rebore, go with the malossi. If not GS. But never the stock meteor!

Get this one if shopping for new and forget anything else. Stock timings and superb quality by Primatist in Italy. Mazzucchelli's quality is a bit questionable ATM...

https://www.sip-scootershop.com/en/product/long-stroke-crankshaft-sip-premium_45021500

Thank you,

I know Scooter Mercato can order anything from SIP and shipping is way cheaper.

I saw a video by That Scooter Shop which showed how the timings improve just by switching to the long stroke. The 60mm fully uncovers the ports, while the 57mm does not.

I also found a series of videos that was very helpful. Here is a video on SI carburetors. It filled in some of the gaps in my understanding on jetting, slides, AC's and mixers.

I'm not sure at this point if I need a rebore. I'm pretty sure the cylinder will clean up with a quick hone. After honing, I will measure it with a bore gauge and see what I get. If it checks out, I will go with the standard size GS piston. They seem fairly easy to find. It's the larger bore sizes that seem scarce. My stock piston is probably salvageable, but I don't want to run it.

Not much of an update. Drilled the float bowl on the Stella carb so I can try bigger mains. The biggest jet I have is a 128. If that doesn't make it splutter, I'll be surprised. We get days where it's cold, but the roads are clear and dry. I can put up with it long enough to warm up the bike and try it at WOT. At some point, I may go back and revisit the timings and squish. The bike still has that feeling of power kicking in suddenly at higher rpm's. Having ridden it for awhile, I think I might be better off with lower timings. I'm going to get some more shim stock and play with it a bit.

Trying to get the 200 in primer. The biggest obstacle is the cold. I set up a paint booth in my garage with big tarps.

My plan is to get the metal nice and warm with halogen work lights. I have 4 sets. So, warm up bike, get the hot lights out of the way, shoot primer and bring back the lights when the fumes have cleared and heat overnight. After that, I can bring it down to the basement. I also keep the primer in the house and warm it up in a pan of hot water.

Topcoat can be trickier in the cold, but the same method should work. Paint tends to flow out better when it's cold and dry, than hot and humid.

Depending on how the primer goes, I may just paint it myself.


A little rattle can gloss to help me planish out what's left of the dents.

Could you use electric space heaters? I've used them with filters on back for other projects not automotive type painting.

I used a radiator space heater inside my paint booth to re-skin and paint my boat in the cold. That's how the heater got its patina.

Yes, I have a garage heater that runs on 220v and a big Buddy propane heater. It makes things more complicated, but it works.

Got the carb back together and back in. Kicked right over and went for a ride around the block which tells me nothing. Dark and in the 20's. I could have warmed it up faster with a cigarette. The missus about to get home and the kids to feed.

Everyday something gets done is a good day.

If the pilot jet is near correct, one test for an air leak is to undo the idle screw. If it gets to near loose and still running, there is possibly an air leak.

Good tip. Thank you. I did pressure test the engine after rebuilding. No idea if the pilot jet is near correct as I'm still working on the main. Pilot is currently 40/120, 140AC/be5/128.

The 125 I had in it was clean at WOT, but lots of 4 stroking at low throttle and not clearing up until around half throttle. Once I get the MJ sorted I will look into that. I am thinking 125 will be close.

Yeah, the space heater shuffle. My old garage has a natural gas heater. I still have that house and was considering bringing the whole shit show there to paint, but it gets complicated.

I was also looking over my new digs and found that it would be pretty easy to T off the gas surface and add a short run to the garage. A couple years back, my neighbor and I rented a trencher and ran the gas out to the garage. The trencher just bogged down and I ended up hand digging most of it. Those were the days of the anything goes, womanless household where I could play with natural gas and put gas tanks in the drier.

The pressure test doesn't test the exhaust clamp or the carb/box gaskets. Try the idle test and see what happens. At least you get some idea.

If you want your scooter to run reliably for the longest time Its very important to know what number main jet makes WOT splutter bad. What happens at less than WOT is not so much an issue with the main jet per se. If it won't splutter at WOT, there is a very long list of possibilities to work through.

10-4 on that. Do mean the idle speed or mixture screw?

Idle screw. If the pilot jet and mixture screw are ballpark correct. Undoing the idle should cause it to reduce rpm, then cut out. If the pilot jet is way too lean or there is an air leak somewhere, it will stay running, maybe even with the idle screw unseated.

Thanks! I will give that a try. Nice to know those tricks. The Stella reed block can be hard to seal.

Had long conversations with Matt and Dave at Scooter Mercato. The 60mm cut crank should work well without making it more difficult to set up and the GS piston is a solid upgrade. I would call this rebuild stock + or basic O-tune.

just watch out that you will need bigger jets because of it. when I turned my p200 back to stock but abandoned the 60mm cut crank inside, the main jet needed turned out bigger than stock by quite a bit.

on second thought it may not be quite as true with the reed block, so take it with a grain of salt.

What was your reason for going back to the stock crank on the 200?

Sorry, I've been jumping back and forth between the LML and the 200. The 200 has the stock rotary valve. It also has a road 2 so I'm expecting to have to upjet anyway.

No jetting today. Our winters have become these mixes of rain and snow with temps hovering around the freezing mark. Today everything is ice.

Tuned up all my work lights. Should work fine for primer. I'm definitely farming out the top coat. I'm a so-so painter even in the best conditions… which don't happen here until late April or May.

I went from a Malossi 210 with pwk carb back to stock top end and carb. The 60mm cut crank stayed so I didn't have to split the engine. The jetting was richer for a stock setup because my rotary pad was opened up and it was a cut crank too. Longer intake duration = more air = need a bigger main.

Thanks. I will go through your thread and read up on your reasoning. Can't remember if you were selling a stocker or going back to basics to keep it simple.

Just enjoying a full catch up on things.

My $.02 on jetting (you are probably way ahead already):

On your 200, drilling of the float will have major effect on size of main.
IK it originally wouldn't splutter at 125main jet - but after drilling it might - or perhaps a bit larger. In any event - you may find yourself back in the teens for good solid jetting, once drilled. Really critical to get it heat soaked as you get closer to nailing final jetting - if you want to refine it to factory like smoothness.

On "idle screw" (it was the mix, as you sorted out), it's not always a leak if it doesnt have an effect when you turn it, sometimes it's just the wrong idle jet so its not in the range where turning is very effective. If it doesn't respond to turning - go richer or leaner first with jet and test again - before you start stripping parts off...

On pad. Get it super clean. I think you have a bead blaster? I would be sorely tempted to hit it on light pressure with this. The texture will only help and it will really get into the crevices to clean out the oil. When you order your crank, get yourself two dummy bearings.

This will allow you to spread JB weld - or the like - on the pad, and then put an oiled up crank in place - and assemble and lightly torque the cases. this will give you a smooth finish on the pad, that is aligned perfectly with your crank.

It will also keep the epoxy that squishes out, out of any sealing surfaces. Once mostly but not fully cured, you can split the cases again and use a razor to clean up areas that should not have any epoxy hiding behind (or on) the crank.

Panel beating is impressive!

EditIf usii ok Ng the crank, a very thin piece of paper or wide feeler gauge at .002mm thickness as a shim will give u the specified clearance. U don't want zero clearance between pad and crank.

Was going back to stock to sell. You need the detaining thread though, not the the tuning thread.

Thank you!

I'm actually jetting the Stella…and building the 200, but I gotcha on the pad and the testing the idle jet with the mixture screw. Drilling the float bowl, switching from undrilled to drilled air filter changes everything. Heat soak takes some doing at 20*F. Hoping for an oddball day in the 40's.

The pad…That's how I'm gonna do it. Soda blast or fine bead. No machining experiments.

Sdjohn, I will check out your detuning thread. Seems I have come across it before.

Testing out my arctic paint booth. It's 19* outside. Not sure if this is gonna work. I'll have to wait for a warm spell. I fucking hate winter.

Does it have a ceiling?

Sort of. Tried the Buddy propane heater. Works much better than the electric.

I ask because, I had a large room 24' x 36' I couldn't heat, winter in Minnesota. Once I put thick plastic on ceiling as an air and vapor barrier, I had to turn pellet burner down from running wide open to low. Room was 100°+, by the time I had plastic up and taped seams on far end of shop. Some tape to seal up seams and stop air escaping can help a lot.