Trying to fix my neighbors Coolster moto. I think it's a 50cc but I don't see any marking to indicate either way.

It will start with starting fluid and run for a few seconds bit then dies. Gas is fresh. New carb maybe?

Thanks!

 

Fit a new plug and clean the carb out, remove float bowl and jets, blow them and the holes they came from out, with compressed air. If that doesn't fix it, check compression, less than 90 psi and they get bad to start. Check valve clearances if compression is down. If valves are OK, time for a top end rebuild.