I have posted the following in the CRF450 forum, but since there are some very knowledgeable people in the CRF250 forum (Charlie comes to mind:smirk:), I double post. I have a 2004 CRF 450 that was always easy to start until the valves zero'd out. I put SS kibblewhite, and I also re-ring my Wiseco piston. I also "played" with the decompressor arm clearance, but made sure that I was eventually in spec (0.011 + 0.014) ... The bike fired up first kick BUT the compression is WAY higher than it was before. It almost looks like the decompression is not working. Is it due to the stronger KB springs, new rings on the piston, did I mess up somehow the decompressor arm clearance ???