Why not give your engine the edge with a Raccoon tune.   Gasflow / Porting / Intake Mods / Bigbore Kits here at Raccoons we have a big interest in sports mopeds, so the plan was to make a very quick Yamaha FS1E. Years of R+D have created one of the country's fastest peds with 14bhp and 80+mph !   below is  a link to youtube to see it in action  http://youtu.be/kzOpMs4WJTg