Hi,

I'm looking for advice on whether I should replace the engine seals and/or clutch plates on a '78 P125 I recently acquired. The scooter is in really good condition. It was stored in a basement since '88 and has 2250 miles total.

I am planning on cleaning out the carb and the fuel tap, getting a new battery and coil (which isn't working), and replacing some of the cracked rubber bits. When I pulled the flywheel and stator to take a look at the flywheel seal, the seal looked pretty good. However, since it has been sitting for 24 years or so, I thought I should seek the advice of some more experienced mechanics.

I've attached some pics.

Thanks,
Chris

I would not trust 24 year old seals. I would expect the bearings to be ok though. good luck.

replace it if it leaks, but you're probably on borrowed time on those.
most likely would run fine for several hundred miles then start leaking.

If the seals are ok now, they won't last long. Also, I'll bet you will need to replace the fuel tap in the near future. Good luck and have fun!

Hear is what I would do:

- fill gear-case oil
- New Gas/oil Mix
- Spray penetrating oil in cylinder and let sit overnight.
- New Plug

AND FIRE IT UP! Then I would ride it locally.

That said, IF it runs I would then order the following immediately.

-NEW Gaskets/seals
-NEW Crank Bearings (Upper and Lower) The way I see it why split the cases Twice.
-New Battery
-New Tires /Tubes.

Enjoy your scooter.


Once she starts acting up when the seals go (High revs/gas in gear oil etc...) set a weekend to replace everything.

Thanks to everyone for the advice.

I will plan on replacing the seals and getting a new battery. I pulled the engine last night and will split the cases over the weekend to check on the condition of the bearings, cruciform and clutch plates.

I will definitely be replacing the tires and tubes as I've heard from a friend that they will not be safe on the road.

Chris

She's a beaut! Great find. enjoy the ride.

Serious question, not trolling: The scooter has 2250 miles. Do bearings just go bad after a time? I can see seals, being rubber and all, but...I am super cheap and, if it was me, I'd replace the seals and leave it at that. Why open it up twice, yes, but...why replace something you don't have to.

I did see a GS with bad bearings, but it had 15k miles and the original seals from 1961.

IF it had any moisture in the cases or through the exhaust during it's time sitting they are probably rusted. Rust is an abrasive, so if they have any rust they will be done shorty.

For less than $50 you can avoid $200+ in parts alone when you have to replace the bearings/crank and whatever else is done when they seize.

Not replacing them seems like false economy.

I split the cases over the weekend on the P125. It's definitely going to need new bearings and perhaps some other parts as well. I've attached some photos of some of the parts I could use some advice about.

The oil at the bottom of the engine had mostly gummed up, messing up the DC roller bearing. The drive shaft and gears came out of the rear hub bearing ok, but the selector spindle was stuck in the drive shaft. I got the spindle unstuck with a rubber mallet. The drive shaft and gears look salvageable, but the selector spindle looks pock marked, so I imagine I should replace the part.

The crank also looks pock marked on the rotary surface, but not on the bearing surfaces. The clutch side seal came off with the crank and it looks like there are light abrasions where it looks like it scraped on the crank. I haven't looked at enough broken Vespa engines to be certain, but perhaps the seal failed on the original owner and he ran the motor until it wouldn't run anymore before putting it in the basement?

At what point would you all decide that the crankshaft can't be reused and needs replacement?

Thanks,
Chris
Seattle

Nice looking scoot,does not seem too bad engine wise.A dozen or 2 hours of fun tinkering maybe less if youve done it before.
Just nosey what did you pay for it?
Good luck

I paid $800 for it. The original owner sold it to a friend who didn't have the time to fix it up.

Good price for the condition it's in.
At that price I would go ahead and replace any questionable parts.those pits on the crank are no big deal but the bearings might look like that too and thats bad.
You'll spend a little time with your project and learn to curse in Italian. I like wrenching on mine as much as riding it.

The crank and likely be re-used. I have used worse ones and sure the big end bearing is probably less than ideal, but it can't really hurt anything if it's bad.

On second thought it can probably wear the other two crank bearings out due to extra vibration/slack in the con rod. The motor I built with the pitted crank was for a camp scooter that we only used for the campground. It only was used at low speed and not for long distance. It always fires up on the 1st or 2nd kick, but I am not sure I would want it as a daily rider.

So the pitted spots don't matter much but for reliability and durability I would replace the crank or send it to hot rod AL and have him service it with a new bearing and polish the rust off it.

The plunger on the transmission needs to be replaced, but the bearing surface on the driveshaft can probably be polished if you have a 10" stationary polishing machine/grinder.

Check the primary gear (x-mas tree) and see if there is rattling and/or slack from broken or rusted spings in the cushion/cush gear. If so you may want to get a rebuild kit for it.

Also while you have it all apart remember to inspect the stator and harnness for worn or damaged wires. It's always a pisser when you get the motor running real well, you take it out a few times and then when there's a rally the thing won't start because the kill wire shorts out or the CDI wires break off.

Good luck with it.

minimum get the true on the crank checked over - usually a local motorsport race shop will take it on and its cheap. As mentioned, send it to hot rod al for him to work his magic - he worked over the crank on my VBB - he does a great job (and he's a top bloke also).

are the bearings original italian ones or replacement indian ones? Indian ones in my experience are a crap shoot, as mentioned if in doubt just replace them with some good quality bearings whilst the engine is apart.

If you are on the fence about the condition of anything its probably worth swopping out ....been burnt too many times by re-using marginal stuff then murphy's law kicks in after a couple hundred miles.

Thanks for all the helpful advice.

I've pulled most of the bearings from the cases. They are the original Italian / German ones. I put in a parts order from Motorsport for new ones.

I will probably get in contact with Al about cleaning up the crank once I get in a replacement flywheel bearing so he can swap out the flywheel inner race.

The cush gear springs are ok, but the plates have a good deal of rust on them, so I ordered a rebuild kit.

Thanks!
Chris

I finally got the engine for this P125 running again this morning. I thought I would post a couple of photos from the build. Thanks to Hot Rod Al for fixing up the crank and Rob Hodge for the help with the bearings, the stator and answering lots of my questions.

I had to rewire the stator and change the points and condenser before it would start up. The timing is still not right, so I will have to mess with that a bit before I start riding.

Good job.

That crank looks purty!

nice work.