actualy there are published reports with torn down motors that prove a "hard" break in as discribed by some on this post is the best for the motor according to the published report you should allow the motor to get up to full opperating temp and then do a long hard pull under load (best done by a dyno) and then let off and let cool and do it again not just jam her and go but a real calculated under load run. the reason is that you only get one chance to seat the rings once you have worn off the initial ruffness of the cylinder walls and piston rings you can do what ever you want till your blue in the face and there will be little to no change in the matting surfaces between the rings and the cylinder wall. if you polish them in properly under as heavy of a load as you can they will be near perfectly mated to each other. this was a report on race bikes and they tore the motors down to show the diffrence between the "soft " and "hard" break in.