I have a vespa v50 N, V5B3T, completely restaured head to toe, with engine overhauled. currrently it just made 100 kms.

I always had the problem of stalling when i engaged the first gear. otherwise the vespa starts and idles well.

So now, the real problem.

Yesterday, i was on a busy street on a considerable speed, and the red light came on, so had to stop. from 4th gear to the second. I heard a clicking or breaking noise. the engine stalled. never started again. i thought i broke the gear, but that was not the case because i was able to engage the gears after on.

the flywheel turns fine. just the engine does not start.

can you please help me by saying what might the problem be and where i might start looking to start the diagnosis? I am "technically" declined, even though i own 5 vintage vespas. maybe this one will be the first where i will learn a lesson or two.

thanks in advance guys.