A buddy of mine has got into some trouble so I am trying to off his 1999 yz400. It needs fork seals and a valve adj. Dont know much about this bike but once you get it started it runs like a bat out of hell. If I were to adj. his valves for him could I use the standard shims for the newer 450s or whats the deal on these.Also anybody have a idea for a good asking price. The bike has 150 to 200 hrs. on it.