Nice info here.... I got my 04 apart and ready to toss some new rings in and check the valves while Im there. its got about 100 hours of which about 30 are mine. It runs fantastic still, but I think Im getting some blow-by as teh oil needs changing more frequently. Side note....is it possible to throw the 04 WR450 5 speed tranny in the yz450. Im interested in a 5th gear.