Modern Vespa

Thank you guys!

It seems to turn out really good.
There is some spots of rust all over the body, nothing major though.

The body will get a blast this week. Not sure if I will go for sand or glass. What do you guys recomend?

Another question!
I want to add a new ignition system.
There is a lot of alternatives. Permakit, SIP, VAPE, a.s.o...

Can someone explain or recommend wich you prefer and why?
I have minor knowledge about Electric, but I am aware the difference between DC and AC for exemple.
However I have no idea wich option would be the one to prefer.

SIP = VAPE

No! They have different teeth. One is helical cut and the other are straight cut. Which one do you need, I am not sure. Wait for someone else. But dont pull the trigger yet!

Have you got a machinist friend who could make a small bushing so you could use the original or original type screw? How are the threads in the hole opposite side? If you can do a decent repair on the original, you know everything fits as it should, but w/ the aftermarket replacement piece who knows? It may have a perfect screw hole but possibly just not fit or work quite right.

By the way!
Builded a tool to separate the engine case.
Very non sophisticated, but fixed the job!

It's a kickstart gear.

I'm not 100% sure, but it looks like it might be ok to me. From memory they look a bit odd even when new.

the factory tool works this way, nice work!

Some answers to your questions depend on how far you want to take this.

Having decided to stay with the original casings, there's a few more decisions to make. Are you going to use original gears and all that goes with them, or transplant a later gear set and associated parts? Mostly it's possible but not straightforward.

A related question is what cylinder do you want to use now? That's going to have an impact on how strong your gearbox needs to be.

Did you tell us what kind of riding you want to do on this?

You'll enjoy the VMC. I run it with a Polini box and it's got an absurd amount of torque. Mines geared to 8" wheels and I've topped out at 119km/h so far.

Sounds like you'll need to get the case on to a mill to machine the welds.

Have you decided what you are doing with gears? Are you going to try to fit an EFL gearbox (later P & PX)? They were introduced to handle power better midway through the P series - referred to as "Lusso" I think. But it requires that the whole gearbox including driveshaft matches.
If you want to go down this route, I think the trickiest part is this shaft (input shaft, gear cluster shaft) and matching it to your case - while still maintaining the correct sizes to match to the bearings. There's a number of different ones to choose from.



Don't buy a gear selector until you have made a decision on this.
A very good selector that is in stock is this one - https://www.sip-scootershop.com/en/product/selector-box-kr-automation-px-lusso-cnc-verstarkt_87009100?usrc=kr%20automation

Yeah i figured that to.
Contacted a lokal machine shop, they will fix it for a fair price.

The gearbox feels tricky...
Maybe as you say i will go for the "lusso", however I have not found any good projects that I can read more about this.

Need to get some more information before i touch The gearbox.

I have a friend that is doing the same thing as me with the same engine.
He says he will go with original gearbox.
We have discussed this for a while and he seems to be sure that it shouldn't be any problem.

Here is some photos that are shopping his project.
(I have ported my engine the same way now.)

That transfer porting is pretty impressive! Does that mean you have decided on a cylinder?

I have put a Lusso gearbox in a Super (VBC) case but am not sure of the differences between that and yours. My memory of that is that it all has to be Lusso including the selector box, except for the shaft. And if you are able to machine the flywheel side for a stock PX shaft then so much the better.

At the clutch end of that shaft it passes through the case and is fastened on the outside next to the clutch cover.
Depending how much power you intend to put through it, that area may need to be reinforced. It's pretty tight in there, I think later cases were beefed up a bit but not 100% sure on that.

Check out Safis' excellent work and pics in this post for an explanation of what I mean - Reinforcing engine casing (Post 2431393)

The plate is a little of center. I used a model that was uploaded as an pdf-file.
Never mind, It doesnt matter. It can still be used.

When I putted everything together i found that the cruciform didnt get all the way down in tracks on the output shaft.
Is this correct? Didn't want to unscrew everything again. So I ask here before I do that process again (see last pictures).

Maybe worthwhile holding the plate in place with blu-tack or something similar before you weld it into position... then assemble the driveshaft into the case and check for anything touching. You're probably going to do that anyway sorry, just I would hate to see it go wrong!




Looks fine to me. Seems to be aligned perfectly with the marks where the gear has been running, let's see what other people say.


Ah, of course!
The reinforcement was welded in the case.
Went out very smooth!


Great tip about the gearbox.
I will do that!

I measured the gearboxs clearence. Got it to 0,45mm. Bought a set of shims. Will add another 0.3mm to get the clearence to 0.15mm

I am not able to use shims from both side on my driveshaft unfurturnatly...
I found a lusso gearbox. And the idea to use that instead hit me... however I have read a lot from other users that say that it is possible to use original gearbox up to 30hp with ni problem.

My conclusion is to use the original gearbox. If it breaks, it breaks 😬.
A useful tip I wish I had known years ago...

When you have your gearbox stuff ready to assemble, and you have shimmed your gear stack, put them all dry into the case with a dry gasket. Fit your gear selector box. Now with a torch look through the clutch opening and check for alignment of the gears with the xmas tree. Select each gear and make sure the cruciform does not touch another gear at the same time - if it did when you ran the motor you would hear clicking, which is not good.

You won't get it perfect, but you can make minor adjustments for alignment with gear shims, and with the location of the gear selector (using thicker or no gaskets as required - DRT make steel spacers for this). You could also space the cruciform if necessary a little further towards the wheel side with a thin washer/shim on the selector rod. Make sure you use Loctite on the cruciform when you are happy with the position of everything.

The Lusso gearbox has circlips at both ends of the gear stack, making it easier to move the relative position of the gear stack with shims. Not sure a shim is possible to put on the flange end of your driveshaft.

I think SIPs supersport is the right alternative for me.
However they are made for 62 or 65-teeth primary drive.
My original is 67 teeth, helical.

What is my best option or alternatives with this clutch?