My '92 formula plus will haul ass to about 60 MPH. Then it slowly chugs to about 80 for the top end speed. This 580 -doo is totally clean and runs great. However, I would like to hit the 90-95 range with it...any suggestions aside from engine modifications? Should I regear? Clutch work a novice can perform? Are the clutches even working properly? Is anyone out there familiar with this sleds performance characteristics? I did get rid of the wide 16'' track, which added 2-3 MPH. Thanks for any advice in advance.