Causes why your (Puch) moped engine quits when warm

A frequent issue I encounter from follow moped builders is that the moped starts great but once the engine gets warm, it stops and won’t start again. This is a very frequent issue so we decided to create a page about what the causes can be and how to solve this issue. If you know anything else to be added, feel free to send it to us.


Air leaks also known as vacuum leaks are the most common cause. !! Always check for Air leaks first!! If you don’t know how to check and solve air leaks, we wrote a post about it here.


Another possible cause could be a badly adjusted carburator. For example if you have adjuted your carburator with a cold motor, you need to re-adjust your carb. Always remember to adjust your carburator after driving a few kilometers. Your engine needs to be warmed up!! 


This is closely related to the carb adjustment. If your Jet is to big it’s pretty possible that your engine quits because the spark plug can’t ignite the amount of fuel. 


If you’re sure that everything is set accordingly but the issue still remains, then the chance is pretty big your condensator died. Try replacing the condensator and see if that helps.