Hi crzybudman,Have ya cleaned out the carb and checked the float needle to make sure it gettin enough gas? There could be a few things goin on;1)vaccum leak at the intake where it mates to the engine.2)If there´s reeds in your engine make sure they´re still good,they need changing,yet no one ever looks after them. 3)The other thing to check would be the compression and ignition timing(especially after rebuild)see WHERE its firing at. Also try a platinum spark plug,sometimes they can help if ya have weak spark,over rich mixture in carbs,or for chronic fouling from oil in the cylinder.(only a temporary fix) Hope that helps ya man! Good luck! ;D