I went to yz timing today on my 2000 wr 400 with airbox removed and baffle. I checked the clearance and they were all right on the minimum limit. Intakes were around .005 to 006 and the min specified was .0059in. the exhaust was close too. The yamaha dealer had no shims(NO CLUE). Anyways one yama place told me I'd be fine. So I put er back together. But the plug was white. I just bought a jd kit and installed a 170 main blue needle3rd clip, 42 pilot.(@2200ft, 65 degrees) . It bogged bad and didn't pull well so I put in the 165 main and it pulled everywhere better. Started off with a new ngk plug and rode for about 4 hours hill climbing. It ran so good I didn't think I could be that lean. How long does it take you guys to get a good plug reading on a new plug? I think i'm going to go to a 168 and see if that helps, or should i go to the 4th clip position? That seat is amazingly hard, so I'm going to try to find a cheap way to soften it.