So I've got this problem where my 03 WR450F won't rev past about 5000rpm. I've checked everything I can external of the engine and still not found the problem, so today I've stripped the cylinder head down to see if there anything wrong with the piston or the valves. Although I've stripped loads of two strokes in the past, I've never messed with valves before. The head and valves look fairly OK to me, as far as I can tell, although there's a fair amount of carbon build up. Anyone see anything obviously wrong here?.... [/url] Should I continue and take the valves out? Should I take it to a shop as it is and get the valve seats recut? Thanks for any advice.