Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Only one way for the gas to get into the crankcase on engine, unless it has a fuel pump mounted on the crankcase and run by camshaft. And that would be the needle valve in the carburetor leaking . this only happens when engine is not running. So best to use a gas shutoff valve and keep gas shutoff between uses. Needle valve is not made to be a posiitve fuel shutoff for long periods of time.