I have an 04 yfz 450 with brand new maxxis tires with an extra set of plastics, nerf bars, after market front bumper and grab bar, the 08 motor runs great with no problems. Just got a k&n air filter for it. It also has higher compression and been tuned at h&h in Missouri. I don't ride it very much, been in a garage its whole life. (785)-672-twoseventwofour