.well, you need to determine whether its de-restricted or not...
..all 50cc scoots sold in the US are restricted to 35 mph, from the factory..
..open the cvt cover, and remove the variator..the boss that it spins on should be smooth...
..if it has a bushing, then either have it machined off, or buy a unrestricted boss...
..that'll give you a few more mph...
..there is also the cdi to think about..it restricts the scoots rpms...I'm not sure what method you need to do to de-restrict that one, but i'm sure somebody here will know...
peace