i have a 79 tomos sport it goes 40 flat i didnt do any large modies like add biturbo or a new crank but if you want it to go a little faster take your spark plug and clip the little pice that looks like an upside down L just a little ant the take off the sleave that is known as the air intake sleve it will suck up more air and make your ped go faster you should get at least about 1 or 2 mph faster with those two