Hey I tried this thread for my neighbor on the 250 forum and thought I would try you guys out also, he rides his WR250 and it just quits after a short time maybe a mile or two, almost like he hit the kill switch, then when it cools or after a period of time it starts up and runs great then quits suddenly again. When it quits it won't even think about firing. Could it be a faulty kill switch, the bike has 177 miles on it and its an 05. He just bolted on a powerbomb header and Q2 with a K&N filter could a lean condition cause problems like this?? strange it doesn't seem to be getting overly hot. Thanx.