I have a 2000 YZ 426 and it runs perfect. It always starts on one kick and has more power than I'll ever use! What happens when the valves are out of adjustment? Does it make noise? I am getting loud valve clanking noises when the bike is idleing. It seems that the sound is louder from the top of the motor near the valves and head. I went over to a friends house that has a 2001 YZ 426 and his engine is way quieter. All you hear from my bike is valve noise or knocking noise from the head. Anybody here have a guess as to what it is? Thanks!