Greetings 250F riders, Im normally in the CRF 450 forum. but i have another bike more similar to yours than my 450 its an Aprillia sxv550,its a twin the cylinder heads are a spitting image of the CRF250 heas except the intake port is more straight down. the crf250 valves reportedly fit this head. Anyways I have valve issues, and the aprilia website/forum is full of wankers talking about blinged out bikes and other useless banter so I figured Id check in with some people who i know are intelligent, HONDA riders. And the ones with the same issue I'm having happen to be you 250f fellows. so hers my questions, whats the most economical method of addressing the valve issues? does one really need to replace the seats with beryllium copper and buy the super trick chromium nitrided valves? (I have twice as many to deal with) or do the copper seats and oem valves suffice? or would i be better off with oem seats and chromium nitrided valves? also is it visually possible to identify valve seat material? when I cleaned my head the seats appear to be a copper color. it seems like you guys were having intake valve problems, my intake valves seal and my exhaust valves are the problem im almost wonderinf if an oem crf250 valve may be better than what im currently using.