I am having a problem priming my engine. There are no fuel leaks and the compression on the engine is good. I think the carburetor is leaking because if the carb is off and I blow on the line from the exhaust fuel pours through it but when the engine is cranking and I put my finger over the exaust it won't prime. I removed the carb and placed my finger over the hole where the carb goes and cranked it and I could feel it sucking my finger any suggestions? If it is the carb how can I seal it?