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!
This is single cylinder engine? It is 4 cycle, but check the exhaust for debris, maybe mice have plugged exhaust. Have you checked for good fuel flow to the carburetor from the fuel pump?
What about the exhaust?
You have good compression, and the valves have been set, so I doubt that it is a leaking valve. The air cleaner is new. So I wonder if the timing is retarded?
Do you have the engine number? The single cylinder? Have you looked at the coil and the flywheel, looking for rust or damage?