why would you want to switch? usually people get the bump...

anyways- your crank has to come out the rear of the motor and the back plate has to be switched to a pull start, the 1 way bearing rides on the crank shaft it grabs when you pull the cord and then it slips when it starts cause the crank is spinning after it starts. am i messing you up yet? i think youll need a diff crank that sticks out the rear... better off just getting a pull start motor. or just sticking w/ the bump box.