Tearing down and putting back together a fourwheeler. I race motocross and with racing comes problems and when a problem happens i have to fix it. I have completely rebuilt 3 or 4 fourwheelers ( i dont remember exactly how many). Rebuilding an ATV takes alot of patience. Every thing has to be set just rite or if its not it might not run. Every thing has to be tightened down to torque. If you over tighten something, you could strip it out. If you dont get it tight enough it could leak or fall apart. Every thing just has to be done rite the first time, becuase if you dont you might be able to get away with it for a little while but it will not last near as long as it would if you do stuff rite.