Modern Vespa

I a s riding home and while in 3rd gear the rear wheel seized.This is the third it has happened and had it checked and repaired twice. The Kickstart is stuck but the rear wheel moves .Can somebody please tell me the issue? The last two times it froze in third,maybe I should be in 4th I? dont know.

Welcome to MV from Latina, central Italy.
You will find more answers in the Not-so-modern section of the forum.
Ciao

Hi, sorry to hear this. We really need some more information on this. However, it may just be you have used either too much oil in the petroil mix, or too little!

The carburettor may also be jetted or adjusted incorrectly. The throttle valve needle may be set incorrectly causing the engine to run too lean.

Other things that may cause it are that the piston rings have not been gapped correctly causing them to expand too much when the engine gets hot.

There are other things too such as leaking crankcase seals that can cause the engine to run too lean. Running too lean can cause the engine to overheat and seize.

What spark plug are you using?

We need to know how much work the bike has had carried out recently. Did they rebore the cylinder, replace the piston and rings etc? Who did the work? Was it you or a friend or a shop?

Come back with some more info if you will.

How's your wrenching skills? Would be nice to see a picture of the top of your piston and spark plug.

Let me find a link to mine seizing up due to running lean because of an air leak.


2007 Stella P200 Motor (installed Polini box exhaust) (Page 3)


Look at page 3 towards the bottom, developed and air leak and ran lean then seized. The top of the piston is very clean and my cylinder head temperature gauge showed I was getting hot. If you can get a cylinder head temperature gauge it can help you notice when this is happening.

sounds like a soft seize piston to me. Jetting problems or air leak as christopher said.

Locked up kickstart sounds like a hard seize.

Can you roll the scoot in neutral?

What happens when the clutch lever's pulled? Can you operate the kickstart?