I have an 03 YZ450 that I am about to sell and I will miss it (bought an 06). The 03 bike is great, jetting was spot on and the motor is awesome and valves perfect. The only thing I had go wrong was third gear lost two teeth about two months ago. The shop that fixed never saw that before and thought it might have been a one in a million metal defect. I didnt abuse it but third gear is where you are usually at on a motocross track (although I think someone else on here had the same problem). After riding the 06 the 03 motor feels really smooth but the bike feels much bigger than the 06. There ya go, great bike!