Modern Vespa

Turned out it was my testing apparatus that was leaking. It's a plumbing sleeve over the exhaust stub with a big pill bottle shoved in. I coated the pill bottle with RTV. The case held 5 lbs of pressure perfectly for a half hour before the pill bottle blew out of the plumbing sleeve. Calling that good. Couple odds and ends to put on and it goes on the Stella for some test riding.

This was my budget engine build: Reused the old crank after a polish because it measured out just fine. Honed the barrel and it measured out too. Gear stack didn't require shims. Smoothed out the rotary pad with some JB, though it ran fine with the scoring it had. New bearings, seals, gaskets, cruciform and a set of big fat rings. Factory squish a carpenter could measure.

I just have to finish the sanding on the P200 frame and will build it up over the winter. Hoping it will be my by-the-book, minimal tinker time, first kick, stock plodder ride when I don't want to wrench on the Stella.

Just about done swapping over the 200 engine on the Stella. I'm getting faster at this. I considered trying a few more jetting combos on the 190, but decided to call it good. I have to admit that I was discouraged that I wasn't able to make it work for 50mph + cruising but I have to put it in perspective. It's otherwise been a great running engine…smooth, quick and lots of power. I also managed to make it reliable as well as sort out the electrics so that everything works and the battery stays charged. I think the stock reed block and si carb are just unworkable for this build.

I only rode with the 200 briefly last season before it seized due to a poorly connected oil line. I have since understood that I could have probably just tightened up the oil line and kept riding. I feel better though having gone through everything. I'm really curious to see how it goes. I'm guessing that it will handle the 55-60 cruising much better, but will otherwise feel pokey. It will be a good baseline to compare stock vs mildly tuned. Good to know what your expectations are before getting in too deep.

Fingers crossed.

Question about break in:

Old piston and cylinder. In spec with plenty of clearance. New rings.

What kind of break in should I do? I would imagine it's a lot less than a new P&C. Thinking the usual speed up, slow down x 10 followed by a tank of varied riding, then anything goes.

Break-in is pretty much a myth at this point.

Your piston rings will bed themselves almost immediately and most of break-in was about getting all the swarf out of the motor and wearing down any rough edges on gears, etc., especially the gearbox. That's why break-in calls for an oil change at the end of it.

Lotsa folks on Youtube have done engineering grade analysis of identical motors with differing break-in methods (including warm up, ride like stolen) and never been able to find a measurable difference in any aspect after 1,000 miles.

Personally, I like to do 2-3 heat cycles before I ride it like I stole it, but that's mostly to get the hi-temp paint on the cylinder to cure right.

Thanks! Kind of what I was hoping to hear.

Started up and went for a short ride. All went fine but gear selection was stiff. After awhile I couldn't get it into first. Needs some cable adjustment.

Feels kind of heavy and sluggish compared to the VMC engine, but with lots of low down torque. A different kind of ride. I also started with a pretty rich main jet (125).

Shifting troubles were due to a frayed shift cable in the headset. Replacement went much quicker than the last time. Nice and smooth now.

Went for a longer ride yesterday with the 200 engine. I really like it. Big dumb lumbering power. Really forgiving to ride and a third gear that goes on forever. Perfect for easy cruising even at higher speeds…quiet, rumbley and low revving. CHT's didn't get above 230F. Feels like it was designed to be hard to break.

I can see why some would find it boring. With the VMC 187, the power is always right there when you want it. Once you've had a little taste of it, it's hard to get it out of your mind. It illustrates perfectly the need for more than one scooter.

Then you kit P200 motor 🤣 and the fun begins again.

For long distances, even I'll admit that a mildly tuned P200 is really a wonderful thing. Sure, it lacks the raw excitement, but it ups the power and torque and doesn't have to be screaming while you ride.

Today I did the ride that I had to cut short when the 187 started getting too hot a couple weeks back…across the lake to NY State from Vermont. I only did about 50-55. Those old Escort shocks gotta go.

I really wanted to get some video of my route to work while there was still fall foliage. The 200 handled it easily with CHT's hitting 260F for a couple seconds, but mostly much lower. I didn't put a short 4th in when I rebuilt because I wanted to see for myself. Yup. It's a great idea as well as some mild tuning. I will post some video when I can edit it a little.

Back to the VMC 187 for a minute…

One of the possible causes of high CHT's that was mentioned was the small size of the stock Stella reed block. I have read up on a number of builds that had similar issues which ended up going with a side draft carb and 4 petal reed block. The rotary crank probably isn't helping either.

I was considering this, but it's really more time and money than I wanted to spend on this particular engine. One idea that came to mind was detuning; lowering the timings and compression ratio. It would be less exciting, but hopefully more useful for the type of riding I do. Eventually this engine is going on my VBB. I know something like a DR would probably run fine with the stock reed and Spaco carb. Would it be possible to do the same with the VMC?

Thanks

"Run fine" and "DR" don't land in the same sentence very often

Mostly I hear two kinds of comments on the humble DR: (1) it's old tech and not very good, there are better kits now or (2) yeah it's old tech but it's easy to set up and way better than a stock cylinder and it's cheap.

I usually don't hear people dogging the running, other than piston slap.

Two words: Head Leak

is it worse than stock cylinders? the whole lack of head gasket or o-ring mystifies me on cylinders without

I think it is. I ran through a lot of DR's when I was getting started on tuning and they always leaked. Not even lapping and copper spray seal would stop them most of the time.

Someone said in a discussion about them at the time that they took one to a machinist friend to see what he could do and the machinist said the cylinder deck had "more waves than the ocean."

interesting, but I guess we should probably get back the question, which was whether he could effectively build a mild tune engine like a DR by using his VMC and select components.

I wasn't considering running a DR. My thinking was to set up the VMC kit closer to stock timings and compression ratio to reduce heat. I mention the DR because it's essentially a stock cylinder with a larger bore. Or even setting it up more like the Polini kit, which didn't have issues with temps.

Didn't someone on here do a plug and play with a VMC recently, Maybe? I think I remember reading about it anyways. Maybe Ray8?

So glad you have a usable scooter again. Stock 200 is solid and dependable. Not being very exciting is the best bit about them.
An o tune really wakes them up though. My o tune has a stock 4th and pulls well. In fact the whole scooter feels smooth like stock, just much quicker.
Having the 200 in the same frame does confirm the 190 issue was the engine.

Thanks! Yes it works fine in the Stella frame, with the PX Stator that finally keeps the battery charged and everything working. The Spaco 26/26 seems to work fine too; standard jetting with a 120 main at this point.

The idea of building a tuned engine is much more appealing when you have at least one reliable scooter to ride. Riding season is short here so not having the worry of missing it really helps.

The 200 engine will go in the 77 P200e frame once it's painted. Not feeling the need to upgrade the front drum brake with this engine.

I will revisit the 190 engine when the VBB frame is closer to ready.

Next up is the VR-1 engine, which will go in the Stella. Still in the parts gathering stage.

Weather has been crap, so I worked on the Stella seat. Made a new plate for the lock, cleaned up the hardware and fit a new seat cover.

Posting a video of the ride I have been wanting to do for awhile. My route to work, partly on 2 lane state highways. This is part of the trip back from NY to VT.

where did you get the stella seat cover? looking good.

Got it from SIP via Scooter Mercato.

So you just look for an LML seat cover?

Seat looks to be the same as the 98/MY Piaggio so I believe the available covers are the same too...

https://www.sip-scootershop.com/en/product/seat-cover_79005100

According to my order, it was this one:

https://www.sip-scootershop.com/en/product/seat-cover_79003000

It's usually out of stock at SM.

Cheap, but it seems to fit pretty well. I will have to cut it out where the lock goes. Wasn't hard to fit. I still have to staple it.

Looks like better quality. Mine didn't come with a belt. I will be cleaning up the old one.

Went for a nice long ride yesterday after bolting on my refinished seat. Much more comfy. Beautiful afternoon. Rides like this are gravy this time of year.

Getting used to the gearing on the 200. 3rd gear has to be wound up to 6,000 rpm for a smooth transition to 4th. Took it on Route 7, a necessary evil for getting to there from here in Vermont. It handled it quite well. Mission accomplished in terms of a reliable bike that isn't limited by power or mechanical problems.

Switching to the 200 has made a light bulb come on in regards to tuning. When a newly built engine is not working to expectations, it's often not just one thing. Gearing, timings, carburation have to compliment each other. I mean I knew that but… I think throttle position is part of it too.

Maybe I have potential as a tuner after all. Which doesn't necessarily mean building a fast bike, but one where the engine built performs like the one on paper. That and I have been chewing away on the 187 in the back of my mind. I never completely let go of these kinds of mechanical puzzles.

Yesterday I pressure tested it. There is an air leak around the screw holding the reed block on…for starters. Pressure was down to zero within 15 minutes. I don't know if this is enough to cause the high CHT's. I was also thinking how the gearing, power band and carburation really don't work well together for cool 55 mph cruising. This was pointed out to me, but I'm only now just getting it.

Sorry to blather on.

I took off the strap on my seats. I don't like sitting on them..

I really dropped the ball on this. Between making the Stella a reliable rider and bulletproofing the bus for a 2000 mile road trip, I completely walked away from this project when riding/camping season started.

Now it's freezing out, so I got back to it earlier this week. Pleased to find I had made it pretty far last time I was at it. It's going pretty quickly, spending an hour or so every evening.

I'm resigned to painting it myself. Garage paint booth is still set up and I really have to get good at it in order to eventually paint my bus. No way for me to strip, prep and send a whole bus to a shop without having it off the road for a season or three.

I will start by painting the inside of cowls, glove box, etc until I get the technique down. Then on to the visible parts.

Got the underside and wheel well sanded last night. The gator skin coat of epoxy has made it all take longer. Ideally, I would have sanded down the epoxy with a DA, sprayed on a couple coats of high build primer and sanded that.

The extra time and aggravation of sanding epoxy (as compared to high build) is still much less than hauling it all out to the garage and recoating with high build.

Amazing how lumpy and bumpy these things are from the factory assembly process. A lot of it gets covered with trim that also supports the body work. Leaving all that original and honest.

Making fast progress and seeing the light at the end of the tunnel.

Pretty much got it surrounded. Down to a few rippley spots that won't even show up on camera that I have chased a few times. I was briefly tempted to try heat shrinking them, but that can get away from you real fast and make you desperately wish for the problem you had started with.

I reserve heat shrinking for panels that are severely stretched out of shape, not for fine tuning.

A swipe of glazing filler here and there will get it done.

Onward.

Moving along. Swiped a layer of icing on some spots I couldn't work out any further. Got really close, so I almost didn't bother. Couple of short evenings of sanding to feather it out. I think it will improve the final result. Glad I took the extra time.

Looks silky smooth…

Got my garage spray booth set up again…actually I never completely took it down. I enlarged it a bit to include a desk space, but the mansard effect makes it more cozy;). I also got a couple more led ballast-type lights so I could see what I was doing.

Dragged all the bits up to the basement after work last night, reprimed the cowls and spots on the frame where I had filled or sanded through. Have to leave it a couple days to thoroughly cure as I went pretty heavy on the cowls.

I still would love to farm out the top coat, but I really want to become a reasonably decent painter. No other way but to practice.

This is the way. And until you become a decent painter, you can practice becoming a decent color sander.

Yeah, color sanding is an unavoidable part of DIY painting. Even if you lay down nice glossy coats, conditions are always imperfect. There is always something to fix.

The worst is when it flows out nicely, then 2 minutes later, odd chemical things happen because you looked at it wrong.

When I repainted the GL after the crash, the glovebox cowl developed pinholes in the clearcoat three times. I sanded back down to base and re-sprayed the first two, but after that third, I just said "screw it" and went on.