Engine seems really slow, maybe hitting about 20 mph. My neighbor has a chopper bike that he fitted a bike kit into and his goes super faster than mine and screaming down the block even though he has a hairline crack in his head and other stuff going wrong with his engine. Mine should be going way faster than his. Ive probably ran about 1 gallon of gas through it and im still running 20:1 ratio, just changed the spark plug to an NGK and also my neighbor did a carb mod. What could be the problem, getting a bit frustrated :/