I've seen posts on here where people use race gas to try and make up for a lean condition instead for proper jetting. My buddy done the same thing and his mods are full gytr exhaust. Mine are cam mod, stock air box mod not lid off, exhaust mod, and a dyno jet kit. we went riding yesterday with a buddy on a moded canondale. We got out on the pavement and lined all three up and did a roll on in second gear. Needless to say the canondale was never in the pitcure. My stock moded 450 out ran my buddies with full exhaust(no cam mod or jetted) by 5 bike lenghts. He could'nt belive it so we did it 4 times with the same results. After the 4th race I looked down at his pipe and it was glowing red hot all the way back through the mid pipe. Obviously the race fuel isn't near enough to help with the lean condition and I'm sure there is alot of unfound power waiting to be unleashed after it's properly tuned. The money spent on race fule after a few rides would pay for a jet kit.