Modern Buddy

Just bought a Stella 2-stroke from a gentleman here in town. Doesn't run, the piston's stuck. Took the whole top of the engine off, it's nothing in the top end. Guy I bought it from said it's the rod and bearing but he couldn't split the case to get to it, broke his flywheel tool trying to get the flywheel loose.

So what I'm looking for here is:

Does this sound like what's wrong with it? I have the top off, and the piston does /not/ move.

How do I go about splitting the case?

Any advice on working on these motors?

Could be the crank bearings.

Piston seized; how does the cylinder look?

See:
http://www.scootercentral.net/forums/vi ... 14&t=19212

And:
http://www.scootercentral.net/forums/vi ... 2&p=181939

This should give you an idea of splitting the cases:
http://www.scooterhelp.com/tips/engine/ ... vespa.html

And:
http://www.scooterloungeonline.com/stel ... ecrankcase

We have the service manual here if you don't have it:
http://www.modernbuddy.com/pdf/Genuine_ ... Manual.pdf

Cylinder looks great actually.

WOW that's a lot of info, haha! Thank you SOOO much. Going to get cracking on this tomorrow afternoon!

So have you removed the cylinder or is it still on with the piston inside.

Before splitting the cases you will need to drop the motor. Get a copy of the Haynes red manual for P and PX Vespa scooters. Star is what the Stella is called in other countries so this book includes your scooter. Very detailed information. It doesn't have everything...but it has A LOT of information and step by step walkthrougs.


I've heard of breaking a flywheel before but not the removal tool.

If it's worth it depends on several things. Initial purchase price, how tooled up you are, skill level, parts needed etc. etc. In general stock replacement parts for a Stella 2T motor are reasonable to cheap...relatively speaking. I would go with upgraded bearings and crank.

Here is a link to a tear down and build of a modified P200 motor that I am almost done with. Remember I am building a highly modified motor. A straight rebuild will be easier...and MUCH cheaper.
viewtopic.php?t=18355&highlight=cannonball

Eric gave some great links. I would also suggest Scooter Help
http://www.scooterhelp.com/. Tons of great info but can be difficult to find. I usually use google for things such as clutch scooter help.

Post some pics of where you are at etc and we'll see what we can help with. I'm laid up a bit for a while and will not be getting back into my shop for a while but I can (hopefully) point you in the right direction!

BuddyRaton wrote:So have you removed the cylinder or is it still on with the piston inside.

Before splitting the cases you will need to drop the motor. Get a copy of the Haynes red manual for P and PX Vespa scooters. Star is what the Stella is called in other countries so this book includes your scooter. Very detailed information. It doesn't have everything...but it has A LOT of information and step by step walkthrougs.


I've heard of breaking a flywheel before but not the removal tool.

If it's worth it depends on several things. Initial purchase price, how tooled up you are, skill level, parts needed etc. etc. In general stock replacement parts for a Stella 2T motor are reasonable to cheap...relatively speaking. I would go with upgraded bearings and crank.

Here is a link to a tear down and build of a modified P200 motor that I am almost done with. Remember I am building a highly modified motor. A straight rebuild will be easier...and MUCH cheaper.
viewtopic.php?t=18355&highlight=cannonball

Eric gave some great links. I would also suggest Scooter Help
http://www.scooterhelp.com/. Tons of great info but can be difficult to find. I usually use google for things such as clutch scooter help.

Post some pics of where you are at etc and we'll see what we can help with. I'm laid up a bit for a while and will not be getting back into my shop for a while but I can (hopefully) point you in the right direction!

I'll take some pictures in a few here. Cylinder's off, looks smooth and clean inside. You can only turn the flywheel about 1/4" or so either way.

Is this version of the manual the same? It doesn't state Star 2T on the cover.
http://www.ebay.com/itm/1978-2009-Vespa ... 8a&vxp=mtr

All the ones that do come from the UK, so it'd be a wait to get the manual.

My purchase price was $250 delivered. I've got a fair deal of tools, ordered a flywheel puller. Relatively skilled, I've worked on a lot of 50cc scooters and our Jetta. I feel up to the task anyhow, and if I'm not, well I'll learn a lot on the way, ha! My biggest concern is not being able to positively identify what's wrong once I've split the case.

Nice score!

The Haynes you linked is fine. Sounds like you will have some stuff to learn but are up to the task! I would suggest also ordering a clutch holder tool. You can also either order or make your own clutch compressor tool, might as well rebuild the clutch for about $20 while you're in there. You will also need a torque wrench.

I would start by making a parts list. Gasket sets, bearings, oil seals and probably a crank (I think the big end is shot).

For this I think your best bet would be to call Max at Scooterswest and David at Scooter Mercato (bearings). Both are good guys, tell them what you are up to and they will help with those small things and the might as wells...(as long as the cases are split might as well replace the cruciform. It's a $20 sacrificial part.)

Also check over on Modern Vespa Not so Modern forum. Lots of rebuild info including general needed parts.

Here is an example http://modernvespa.com/forum/topic12074 ... 9259b5b76a

BuddyRaton wrote:Nice score!

The Haynes you linked is fine. Sounds like you will have some stuff to learn but are up to the task! I would suggest also ordering a clutch holder tool. You can also either order or make your own clutch compressor tool, might as well rebuild the clutch for about $20 while you're in there. You will also need a torque wrench.

I would start by making a parts list. Gasket sets, bearings, oil seals and probably a crank (I think the big end is shot).

For this I think your best bet would be to call Max at Scooterswest and David at Scooter Mercato (bearings). Both are good guys, tell them what you are up to and they will help with those small things and the might as wells...(as long as the cases are split might as well replace the cruciform. It's a $20 sacrificial part.)

Also check over on Modern Vespa Not so Modern forum. Lots of rebuild info including general needed parts.

Here is an example http://modernvespa.com/forum/topic12074 ... 9259b5b76a

Okay, so I have now purchased (and am awaiting in the mail) the following:

New tires - mine look shoddy.
Engine Gasket Set
Flywheel Puller
Non-OEM crankshaft

And a bearing/seal kit containing:

1. 1Pc Bearing 1838001-C3
2. 1Pc Bearing 6204
3. 1Pc Bearing 6302
4. 1Pc Bearing 253815
5. 1Pc DC Roller Bearing
6. 1Pc Piston Pin Bearing
7. 1Pc Bearing 6202ZZ
8. 2Pc Needle Bearing 2212
9. 1Pc Needle Bearing 2016
10. 21Pc Lay Shaft Rollers
11. 1Pc Clutch Oil Seal
12. 1Pc Rear Wheel Oil Seal
13. 1Pc Flywheel Oil Seal
14. 1 Set Engine "O" Ring Kit
15. 1 Pair Kick Pad (Buffer)
16. 1Pc Front Drum Plate Oil Seal
17. 1Pc Front Drum Oil Seal

Anything I'm missing at this point?

fly wheel holder tool
clutch holder tool
Clutch nut tool if castellated nut
cruciform
clutch rebuild kit

What crank are you going with?

BuddyRaton wrote:fly wheel holder tool
clutch holder tool
Clutch nut tool if castellated nut
cruciform
clutch rebuild kit

What crank are you going with?

Already have the three tools. Forgot that you'd mentioned the cruciform, will look into that as well. As far as the clutch rebuild kit is concerned: how necessary is that at the moment, or how can I figure out if I need it for sure or not? Being $100 or so I'm hesitant on just ordering.

This crank:

http://www.scooterwest.com/items/?_page ... 54%29/1914

You need to pull the clutch in order to complete disassembley. Parts for rebuilding the clutch are less that $50. It's not a must do...but I would. If it has been sitting for a while I would at a minimum take it apart and resoak the corks.

BuddyRaton wrote:You need to pull the clutch in order to complete disassembley. Parts for rebuilding the clutch are less that $50. It's not a must do...but I would. If it has been sitting for a while I would at a minimum take it apart and resoak the corks.

Ah, the kit on scooterwest is $105, I'll poke around elsewhere.

BuddyRaton wrote:You need to pull the clutch in order to complete disassembley. Parts for rebuilding the clutch are less that $50. It's not a must do...but I would. If it has been sitting for a while I would at a minimum take it apart and resoak the corks.

Grabbed new corks and odds and ends locally, they didn't have springs in stock.

Also grabbed a flywheel puller which promptly stripped itself... Pic here:

http://imgur.com/bCcyKZU

Screwed it all the way in by hand, gave it a 1/8" turn or so with the wrench to make sure. Didn't force it at any point. Once it was on all the way, took a 10" wrench to the bolt, hand force only, and stripped the thing... This is the flywheel from hell! :/

I'm not a big guy either, no serious force put on the bolt or anything... The flywheel's threads are completely in tact thankfully.

Any advice on removing incredibly stubborn flywheels?

Got the flywheel off and the case split!

I still don't have my manual yet. Waiting on that and the new crank.

Nice job! Never heard of the puller stripping before
, was it the right one?
How did you get the flywheel off?

With your next order also get new clutch and crank woodruff keys

BuddyRaton wrote:Nice job! Never heard of the puller stripping before
, was it the right one?
How did you get the flywheel off?

With your next order also get new clutch and crank woodruff keys

It was the right one oddly enough. The guy at the shop said maybe once a year he finds one that's just bad quality. I guess this year that's mine. Went back, got it exchanged, came back home and it came right off with the new puller.

Woodruff keys, got it.

Been a long time since I posted!

Got the engine completely rebuilt, started putting it back together to find that I'm missing both the clutch cover, clutch cover arm, and the flywheel cover (is there a fan that goes on the flywheel on this model?!). So progress is once again halted...

WHICH flywheel puller should I order to fit the RH50?
Does anyone know?

thx!