Modern Vespa

Hello all, just a quick introduction before starting:
I've recently moved to vietnam and I bought an old vespa sitting in a grandpa's garage. Mechanic is a real hobby and I used to work on my previous bikes such as cbr1000rr 2004 and 2009, zx-10 and zx-14.
To start, let's put it staright... when I took the vespa apart, entirely naked, took every single bolts off from engine and frame to make a list of the missing parts based on the part list I got from scooterhelp, I realized that I would never drive a bike that went to a vietnamese mechanic. What you can read here and there, also on this forum is entirely true!! This vespa is a real puzzle and at least 40% of the bike is made of not genuine quick fixes/replacements etc...
Anyway I almost finished rebuilding the engine thanks to a tiny genuine vespa part shop which had 40 years old brand new parts still wrapped in the genuine piaggio plastic (Awesome). Now I'm in the process of rewiring the stator and the entire wiring loom but unfortunately the shop doesn't have any new coils or even the foam pad contacting the crankshaft (see the pictures attached). I think I saw at this small shop that they quite a few parts for PXs and I was wondering what would I need to change the whole electric/ignition/wiring loom to a PX? I'd rather not have to order anything since vietnam custom is pretty hard to deal with so could you guys/gurus give me your advices.

Sorry for the long post and I promise next will be shorter

Well I didn't have lots of advices so i decided to move forward anyway.
I just bought from (redacted) their Bajaj 12v conversion kit with the whole wiring loom. I'll keep you updated with pics and installation if it interests any of you.
For now i finished rebuilding the carb (delhorto 20/20D) and going to fit it today. Any advices on the initial settings?

Also as soon as i'll have everything setup for the engine i would like to make a final check list before firing it on a stand.
Any advices on what the check list would be? I was thinking of things like:
-Check all seal for air leak
-Fuel lines tight
-Squish test on cylinder head (From what i've read >1mm)
-Timing
-Castrol oil in the cranckcase (BTW does anyone know the quantity?)
-Bolts torqued properly
-4% oil/gas mix for break in period.
And whatever you'll suggest me.

Thank you

If you've gone for the 12v electronic ignition kit the timing will need to be about 18 BTDC, rather than the stock timing for super with points (23??)

If it's a 150 2 port barrel your probably looking at around a 98 main jet with the 20/20 carb, but that will depend on exhaust etc.

Crank case oil until it drips out the filler hole..

2% mix, even for break in. Is that a new barrel from [redacted] too? If so you'll want to chamfer the port window edges, check ring end gap, and the piston to bore clearance (as you would for any new kit).

The quality of the [redacted] looms are usually crap, so have a close look at that.

Good luck.

Awesome reply Warhorse! Thanks a lot. Really good to see people as knowledgeable as you.
You are right, it's a 2port 150cc.
Do you think 120 on the main jet would be too much as it was in there at the first place. Also i bought from redacted their polini style tuned exhaust as the original one was clogged as hell. Maybe it could be a match.
Noted for crankcase oil and 2% mix.
I've chamfered the ports 1mm 45°.
The piston and rings are new and i got the original cylinder rebored to have the right clearance with piston but what do you mean by ring end gap? both rings are aligned with the plots on the piston... is that it?
Ok for the wiring loom. Anyway i bought better quality connectors in case I had to change.

I don't know about that exhaust, but I would guess it wouldn't need as high as 120. But you may as we'll try it at that and see how it goes.

Ring end gap is the gap between the two end of a ring whilst they are compressed within the cylinder. Search this forum. I'm sure there's a thread on here somewhere with how to measure and what it should be. Too tight and the ends may meet while engine running and lead to seize.

Ok Got it. Thanks heaps. Will update with pics later tonight after work.
Cheers.

Hi Storf, and welcome to the forum!

I'm not sure how that exhaust will go on a basically stock scooter... they work ok on a tuned motor however. If you are new to the Vespa I reckon you will find a stock type of exhaust will be way easier to tune... they are only $20 at [redacted]. If you stay with the expansion chamber then you really need to to jet up around a minimum of 5 jet sizes and see how it goes... running lean is the biggest issue with a two stroke motor. Stock jetting is about 98 I think but check the manual.

Compress the ring with your fingers and place it in the top of the cylinder. Use your piston to push it down a little way... this will get it square in the bore. Check the gap with a feeler gauge. The ends of the ring should have a gap of around 0.2mm or 8 thou.

Hello Ginch,
Thanks for jumping in and helping.
I used to race Karting in rotax class and usually the way to proceed was to start with a bigger number main jet to be on the safe side and lower it down until optimal. Would it be the same here?
Thank you for the information on the rings gap i'll double check that after work.
For the exhaust I guess i'll start with the new one and if I can't figure it out i'll try to clean the old one once again.
Thank you

If you're used to changing jetting on the kart then you'll be fine - start high and come down until it stops four-stroking.

Sweet, Thanks!
About karting, do you know someone who would have fit some thing like this:

http://www.renntechkarting.com/products_xr50.html

My friend just got his and it's just unbelievable.

That thing is beautiful... pity it still needs a gearbox. If you are interested in conversions and nice motors, have a look at Scooter and Service in Germany, they do some great custom stuff. https://www.scooter-and-service.de/

Wow!!! That's awesome! Bookmarked it. This is some serious Vespa Porn !! Thanks for the link.

Check the ring gap and it looks fine at 0.5 considering your specs. 1 more questions.
- there are 2 rings, a shiny one and a black one. The shiny one has a bit of bevel which means it's suppose to be on the top, right? Just wanted to make sure before I put back the cylinder.

Oh I forgot one last thing before I make the squish test. They supplied this head gasket with the piston but I can't see such a thing anywhere in the genuine part list. I am wondering, is it a vietnamese way to lower the compression to prevent the shity piston from exploding into pieces???

I don't know about the rings. Probably just two different brands. As far as the gap goes, yours might be a bit big. The 0.2mm gap figure was the one my machinist recommends, but in the past I have used this as my guide - which is a bit smaller again. https://modernvespa.com/forum/post1234286#1234286
Actually once you have read that, go back and read the whole thread... it's great stuff.

Forget about squish with the head you have... they are not designed to create squish at all. That ring may be there for a reason but who knows? It may be to lower compression as you say... what octane fuel do you have there?

Thank you Ginch, it really a good read.
As a baseline I watched a dozen time the vespa motorsport enhine rebuild video on youtube. I guess you must have watched it already.
About the ring and after reading the link you sent, I've been thinking that they might have supplied this ring for sealing purposes which would make sense since the machining of head and cylinder are far from being perfect. In the other post he modified his pinasco cylinder to fit an o-ring. Still, from what I understand he was aiming for a squish of aproximately 1mm. Well, being just in a slightly tuned stock form with vietnamese parts, I think I shouldn't be too anal about all this. Attached is a picture of the ports chamfering and the exhaust port a bit wider.

Lil update and once again need some advices.
I finished rebuilding the carb and bought a new air filter. I've been reading almost every posts about drilling holes or not in the air filter heart shape. Considering my setup what would you guys recommend?

Just leave it for now. You want to get it going without throwing too many things into the mix. Once it is going ok, then you can start to play around with stuff like that. Then you'll know if it stops working after a modification what the cause was.

Yep you are definitely right. Actually I'm getting bored waiting for the 12v conversion kit to arrive from redacted. Today and tomorrow is pucblic holydays so got to wait until friday i guess. For now here are some quick shots of the body.
Classy Mat black with no bling bling

Beautiful morning and the high temp paint is dry. Finished bolting it up.
Another day of waiting the parts and I might slpit the case once again for fun hahahaha.

Hello all,
Anyone got any experience with fitting this stator plate? Just received the kit from redacted and first thing that looks a bit odd is that the bolt can't pass through the oval shape holes. Also, how do I set the timing with this, I thought there was suppose to have a mark. Here is a pic.

You might have to drill your own holes to fit the stator, read somewhere that it might not have a perfect fit (for 170$ makes sense), I believe i might have read it on SIP or ScootR$

Thank you Super15066!!
Since it's been 3 days already since my last post i had to move forward.
Now everything has been fitted properly. Now i'm waiting for the plastic fan that they forgot to send me.

Now the new weird thing that makes me wonder, is that the rear wheel axle won't spin freely. It takes quite a bit of effort to spin it (Yes, i made sure it was in neutral). I'm reading every threads i can about this but can't really pinpoint the real reason. What would be your guess? Clutch plates not being oiled because still no oil in the pan? Bent rear axle? I doubt that it's the bearings (Transmission case side and hub side are brand new.)