best thing to do is replace the standard pipe with an aftermarket can (i have a technogas pipe) which is perfect, secondly change the jets in your carb with a slightly bigger diameter jet, then you want to buy some rollers around 4.5grm as these will give good acceleration and top end. you could also spend that bit extra and buy a 70cc barrel and piston from polini or malossi- just dont tell ur insurance company lol, with these mods youll find speeds of around 60-70mph
trickyricky4513
May 2012