Modern Vespa

That's a nice setup. Here's the setup I use...

The right sized rubber caps saves so much time.

End up spending 90% of the time making sure the inner tube isn't leaking.

Update:

After 3 days with the new pressure testing setup installed, I still have 5.5 PSI on the engine. She's tight! I do see about a 0.20 PSI drop in the early morning because my workshop is around 67 Degrees. But when I get home after work ,and the shop is back to 70 degrees, the pressure is right back to 5.5 PSI!

Hec

This reads like a physics test question on Boyle's Law

An airtight engine is being pressure tested. In the morning, the workshop is 67F and pressure is 5.3 PSI. In the afternoon, the temperature is 60F and the temperature is 5.5 PSI. How may cubic centimeters is the crankcase+cylinder volume?

Bonus question: If it takes four hours for the aluminum motor cases to equalize to the new temperature, assuming that the cases have the same rate of heating and cooling as an equivalent sphere, how much do the engine cases weigh?

I actually calculated pressure loss due to the temperature drop using the Ideal Gas Law! It calculated to 0.18 PSI for the 3 degree drop! That's very close to what I'm reading at the pressure gage.

As for the bonus question, I'll need my ASHRAE books to look up the specific heat of Aluminum. She blinded me with science playing in the background!

Hec

Sounds like progress!

I'm a little late to the party but here's my info

VMC Stelvio, 24.24si, polini box, 25/63 and stock px150 gearing.
70.4 mph GPS at 1/2 throttle in 4th. Haven't had the agency to even try WOT in 4th. Also it's still too chilly to ride here, till next week anyways. My ports are flowed and matched. Not sure of the timings, as Gick did the build.

Thanks for the info! What clutch did you use?

Hec

Perfect. Any drop is no good in my book. Always wait 24hrs to check and make sure no loss. That way you KNOW you're good.

I hear ya! I am on Day 4 of the pressure test now and still holding 5.5 PSI! I should probably just let the air out at this point. I know its tight and it doesn't look like the pressure is going to drop any time soon.

Hec

have you rotated the crank around and clocked if you have any leaks in different positions?

Greasy,

I have not. I would need to depressurize the engine first. Maybe by just pulling the spark plug? I tried rotating it a little but with the exhaust plug in and the spark plug in it resisted and I didn't want to force it. Is there a preferred position for the piston? I believe my piston is at BDC now.

Hec

Think the OCD has taken over again. Supposed to be a quick test.

Awe man! Busted!

I did bleed the pressure off and rotate the crank to see if that would cause a loss of pressure. Piston was at TDC and now at BDC. No pressure loss again 24 hrs later. It ain't leaking! It's bled down and pressure testing is over. I hope to have my new clutch this week.

Hec

Well now you know. No matter how much engine stuff I read, there is always one more test, check or measurement I find out about after everything is all buttoned up. Really no escaping it.

stop playing with it or you're going to go blind.

I've never leak tested more than a handful of minutes, except for that smokey which is a whole other story.

Those seals on day six, though:

Who said that? I can't see ya!

Hec

Update

Today I dropped by the paint shop to see how the painting is coming. I was bummed to see that no progress has been made since my last visit on 03.21.23. The paint shop has had it since 02.07.23! The manager promised me they would get back on it and gave me excuses of his people being sick.
At least my new SIP Ultra Strong clutch arrives on Friday! I have been working on the fork in the interim. All new bearings and seals are in. I should have the fork wrapped up in the next few days. At any rate, I should have the engine and fork completed before I get the frame back from the paint shop. I guess I can go ahead and match the 20/20 carb box to the 24/24 carb in the mean time. Running out of things to do in preparation for post paint assembly.

Hec

Update!

Today my SIP Ultra Strong Clutch arrived! The 23 tooth clutch cog matches up with the Malossi cog from the up gear kit too. The 23 tooth clutch cog also meshed with the 64 tooth primary gear.

It doesn't look like I will need to remove much of the tab in the engine case. My plan is to dissasemble the clutch and center a clutch basket window on the engine case tab. This should let me drop the clutch all the way down to see how deep I need to go.

Time to get to work!

Hec

So how much clearance do I need between the engine case tab and the clutch basket? I removed material on the engine case tab using a Dremel and a cut off wheel. I currently have 0.08mm of clearance. I am glad I did this now rather than when the engine is in the frame! It was easy. I prepped the engine using a paper bowl to keep out the dust created!

Then I installed the new P200 clutch cover and quickly discovered that it wouldn't sit flat on the engine case. The clutch was touching the long oil passage casting inside the cover. So I asked my wife for an old lipstick she didn't want and marked the clutch cover oil passage castings. I installed the clutch cover then pulled it off. Whah-La! Lipstick marks transferred to the clutch. I buzzed the clutch cover's oil passage casting that extends all the way to the engine case tab. Now the cover fits perfectly flush. I rotated the engine with the clutch cover installed and can't hear any scraping. Must be good to go!
Now I need to transfer the parts from the P125X clutch cover to the P200 clutch cover.

Hec

Obviously it is not enough. I think 2-3mm is ok. On my case I removed that tab completely.

As long as it goes round, it will run. If it needs extra clearance it will soon make it's own.

Jack,

I agree. I tried to preserve as much of that tab as possible. Maybe I should shoot for 1mm of clearance. I have the clutch linings soaking in oil for now. That clutch shipped dry.

Hec

Tonight I worked on fitting the SIP Ultra strong clutch. I went ahead and increased the clearance between the clutch and engine casing tab from .08mm to 1.0mm. Hopefully that's enough clearance. I assembled the clutch after I let the clutch linings soak in 30 Wt non detergent oil for over 24 hrs. Then I transferred all the parts from the P125-X clutch cover to the new P200 clutch cover. I also fitted the new SIP ball bearing supported pressure plate. That is one cool piece! No more fumbling with the brass plunger and pressure plate. Once I assembled everything I spun the engine over with the kick starter and no scraping. Everything spins freely and smoothly. The one thing I struggled with was positioning the PX style primary shaft retaining plate and funky shaped washer. From what I have researched, the funky shaped washer should make contact with the clutch cover and engine case. I can't get it to touch the engine case. I have about a 0.05mm gap there. Maybe I have it installed wrong? If you have a picture of yours please share.
At this point the clutch nut and primary shaft nut are not torqued down. Only hand tightened.
Little by little!
Hec

Update:

The clutch, pressure plate, clutch cover, primary shaft nut and securing plate are all installed and torqued to spec.

Clutch cover bolts - 6 NM
Clutch Nut - 42 NM
Primary Shaft Nut - 35 NM

I shifted the transmission through all gears and everything works as it should.

Unfortunately the painting is still at least a couple of weeks out. Those guys are sure taking their time.

Finishing the fork next.

Hec

Update: Kind of

This morning I dropped in on the body shop to see how things were going and only slight progress has been made to the main frame. It has been guide coated and block sanded and and another layer of primer applied. At this rate I hope to get everything out of there by the end of May. I thought I was slow!

Hec

I was going to have both my 200 and my VBB stripped to bare metal by Christmas and the 200 painted by February. The 200 looks just like yours. Then cables wiring. My timeline is out the window.

Looks like the shop is doing a nice job on your scooter though.

I am looking forward to the assembly of the completed bike with a freshly painted frame. Everything clean or new. Kind of like building a factory Vespa kit.

Are you going to learn to curse in Italian so the work will have that "authentic" feel to it?

Been on the road the last two weeks. Dothan, Alabama last week and Louisville, Kentucky this week. I will be dropping in on the paint shop tomorrow to see how my body and paint is coming along. I asked the manager if he had any updates. He said, " yes when you stop in?" I said tomorrow afternoon. Stay tuned!

Hec

I dropped in on the paint shop Thursday and more progress was made. The manager said I can pick it June 3rd. fingers crossed.

Roland,

I told ya you project would get finished before mine!

Hec

I wouldn't be so sure.
I will probably get my chassis and lower handlebar part next week.
But side panels not before August. Friend who painting it now have lot of family problems and can't do all quick.

Update:

The painting has begun!
As of today all that remains to be painted is the side cowls and horn cover. The painter is currently working on the gear indication numbers. He is applying red paint in the stampings then he will wet sand the area hopefully leaving paint in the stamping only. The number stampings for 3 & 4 aren't as deep as the rest presenting a challenge to get paint in there. He will apply a clear coat over the numbers when he's done. Hopefully everything will be ready by the end of the week.

Stay tuned!

A few more pics. I'll be picking her up tomorrow! Cowls will get clear coated today.

Hec

Good news mate!

What is round hole in the handlebar cover near speedo and indicator lamp?

Looks fantastic. Pro paint shops can take awhile to get projects like that done, but they obviously did it right. Assembly will be a pleasure on that nice clean frame.

That is for a small Green Led Light with an "N" on it. It will be the new Neutral Indicator light. I am installing an SIP Rev Counter 2.0 Digital Speedo and it doesn't have a Neutral Indication light. I like the Neutral Indication feature so this is what I came up with.

Hec