I scanned about the first 6 pages of this forum and didn't see anything, so I figured it'd be safe to start a thread. Anyway, I'm a two stroke guy but I'm looking at buying an 03 YZ450F. I was wondering if there is anything I need to look out for in particular. Also, I don't really have any experience with four stroke engines so are there telltale signs that something is minor (like a valve adjustment needed) vs. something major? ie, if it starts right up and runs good and I can rail it around the track is it a safe bet, or can these bikes have issues that can only be observed by physically pulling the engine? Thanks!