Modern Vespa

I need to rebuild the engine on my 86"PX125E. The flywheel side bearing is shot causing a wobble that is burning out my stator.

I want to do this as quickly, but as reliably as possible. What parts should I order since the cases will be split?

Thanks

Since the cases are already split, change out all the bearings and seals, the rubber for the kickstart quadrant, and the shifting cross. I'd also take the opportunity to rebuild the clutch (you can get a rebuild kit from Motorsport, I think.)

I'd buy all the gaskets in a kit.

THe bike is showing 33,000kms so I'm wondering if it would make more sense to buy a new engine & install and rebuild the old one over the winter?

Why? 20,000 miles is not that bad. I guess if you have tons of money laying around for a new engine...

In addition to the things Len said to replace, also replace the kickstart gear while you are in there (not the quadrant but the little soft gear it engages with).

Check the gear shim for tolerances.

Buy some new piston rings to tighten up your top end.

Check the other bearings for slop.

I just put a brand new Pinasco 177kit on the top end last year, which has ran fine without issues. How long would it take someone who is averagely mechanically inclined to do the rebuild?

Ah, forget the rings then. It might take a week or so. It's not that bad. Take pictures along the way, use Vespamaintenance.com for a reference, and don't overtighten things when putting back together.

If it were me, I'd rebuild the old one. As you'll see when you open it up (or maybe you've already noticed) the craftsmanship and quality of those motors is just so much better than the new LML ones.

I'm always amazed at the precision of the gear stack and other parts that were machined before CNC technology. The castings were better, smoother and each part seems like it was meant to be on display. Modern parts seem to have more sharp edges, burrs, and just seem to have been made with "how cheaply something can be done" in mind.

That's all just my opinion of course, and I'm sure others have different points of view.

you will need certain special tools as well like a flywheel puller, clutch tool, and if you are removing the crank you need a couple other tools as well

i completely agree. i have a slow rpm grinder i usually use for sharpening chef's knives that i use to shave down parts. all the cruciforms i get have to be cleaned up before they will fit the tolerances of my Italian parts.

its nice to have the leather wheel as well for polishing. usually its for the last bit when doing knives.

I've been shopping and I plan on ordering the following for the rebuild:

- PX Seal Set with 30mm rear hub (how do I know if my hub is 30mm)
- PX Gasket set with o rings
- Carb Rebuild Kit with base gaskets
- PX Bearing Set
- Cruciform
- Kickstart gear
- flywheel puller

Is there anything that I am missing?

Thanks

Kick start rubber buffer

You might need the puller tools.

loose rollers for primary
new tab washer for primary
kickstart gear spring
kick start buffers
clutch push pad and pin
clutch plates and brass
clutch castle nut
clutch washer
o-rings for clutch cover
cruciform plunger (they're usually damaged)
order both hub seals*
clutch nut tool
clutch holder
gear shims

the standard P gearbox takes one type of cross, the EFL type take another-- order accordingly.

*look at your rear axle and determine if you've got an EFL style or a standard style-- this takes an entirely different seal than the other two.

if you remove the circlips to pull the piston get new ones

best,
-greasy