So here's the plug out of my '01 WR426. Yes I know this color is NOT IDEAL. My question is, could my mainjet be the problem? The pilot screw is very rich right now (bike won't even start with the choke on, it's so rich) but once I get the bike started cold, it wants the choke on. I have the stock pilot jet, but a 160 main in it (originally had a 158 main in it for high altitude). when I came back down to my altitude [2200'], a 160 was all I had in my garage. Let me say right now, that from the START I was always worried that the 160 was too lean for this altitude. The yamaha mechanic that helped me rejet for 11,000' told me the main jet would be fine down here, but I'd need to richen up the pilot screw.. So, do I need to go back up around a 170 main? I haven't gone on any rides since I brought the bike home from high altitude. Just fired it up and rode around my neighborhood. Any suggestions? I live at 2200', it's anywhere from 50-60's lately, and humidity is in the teens. Thanks!