I have an '03 YZ450 and it has been very, very reliable. I change the oil and clean the air filter regularly, like every ride. Still has the origional valve shims! I check them regularly, just to be sure be sure. Of my friends that insist on riding red, they are on their 2nd and some 3rd top end. Although I must admit, the Honda will out turn the Yamaha. The Yam is more stable. Once you get used to the way the Yamaha handles, it's a non-issue.