I have US 35 cc engine with Ch igniton set at 29 degree BTDC. I rebuilt the carb. the carb is pumping fuel to the carb just fine when we are flipping the prop. when you stop flipping the engine, the fuel will go back down the fuel line in the tank. When we get it running it will run for a short bust and it will quick we took the fuel line off to run out the fuel and it ran fine for 30 seconds. correct me if i am wrong but the engine should run better with the fuel line on then off.

when I was flipping it to clean out the carb it would kick back a lot it snapped my fingures bad.

give me a idea on what to do now??

Paul