Apparently you don't learn PERIOD. You just said it keeps fucking up on left side so why didn't you fix it the first time? You came here looking for help and you want to tell the experts on here that you know what your doing. I bet if you had a manual you could figure it out no problem. You probably just got lucky with the other bikes. Any Tom, Dick, and Harry can put a motor together, but actually knowing what your doing is two different things.