I built one last year b/c I had the bike already. The bike was fun as hell. I never got to race it. (only started this year) but on the tight cart tracks you should be OK. bigger road race courses (pocono east/ summit jefferson) the bike would run out of steam real quick. I miss the bike alot and the only reason I have a 4 stroke this year is b/c it blew up on summit jeffersons front straight. After it blew up I took the wheels off and put them on the 99 yz 400 I bought with no mods. 99 - 08 YZ's 2 or 4 stroke can all use the same wheels.