So is your engine kitted? I get 43 mph (verified by Garmin GPS) out of my '08 Sprint with just a Biturbo, foam uni-filter, rejetted carb, and 22 tooth rear sprocket. I'm getting about 48 out of a 70cc kitted '01 Targa, with a 15.15 carb, Tecno Estoril, and 27 tooth front sprocket. Time to stop, the GWB money ran out. Peace, Jerry.