[funindamud]

all you haft to do is to grind the inside of the case apart to let room for the new cylinder to go in... i had a 170cc (61mm) cylinder in the buggy at one time... it blew up so i found a used motor on ebay and put it in it... the "shelf life" on the big bore motors are substansaly less (50-80 hrs) and of you stroke it you haft to run a 30percent less RPM than with the 150... ide personally rather have a fast reeving motor with good power all the way through the RPM range than a torque monster with very low RPM range...