I have searched and searched, tried things, but no luck. My 99 WR400 was running fine, then after about 2 hours or riding I noticed the bike idling very high. I turned out the idle adjustment all the way and no help. Things I have messed with are: idle adjustment, throttle cable adjustment, air "screw" adjustment, hot start troubleshooting, air leakage around the carburetor clamp area. The only thing that seems to lower the idle permanently is to pull out the choke (thereby cutting off air, right?). All help appreciated. I just got this bike last week, and do not have a repair manual or owner's manual. I have not checked the ohms on the TPS but I have read that a "bad" TPS would not cause high idling.