only changes the relationship of the pine nuts of the transmission. If you change the rear least two or three teeth increases the final but lose speed acceleration, there is no other way by which those in the maximum speed of your engine. Or Replace it with another more powerful motorcycle, the latter is the most recommendable. The engineers worked very hard to make the design of this bike to be reliable and lasting change does not seem reasonable. One has its design specifications and tolerances calculated scientifically, and the currency with that approach? ok is a reflection of luck.