My scooter project just went 42 MPH on flat roads bone stock 50cc 2T! On 3/4 throttle! Had plenty more RPM's to go, Didn't want to blow it. I am using half Sunoco C16 race fuel mixed with 93 octane pump gas.Old top speed was 35-40. Down hill. WOT. When I get the carb tuned right for more fuel, it wil be an easy 45 maybe 50. At WOT for a long time it will start popping and spitting real bad. Just need to upjet for the cold weather riding i'm doing anyways. This is my normal ride to work and back anyways