Lots of people looking but no one's got an answer.... Come on fellas! Working on a 99 450, bucks and carries on when applying any throttle. Did the usual clean the tank screen, carb, blew out the fuel line, fresh gas and nothing changed... Out fiddling and I guess I turned on the headlights and runs out strong? Take it for a ride(lights on) works great until I turned around at the neighbors and it bucks and spits and sputters for a min and smoothes right out. Out of curiosity I switched the headlights off and died right now, any clues, directions? It's sat in a barn awhile, usual mouse nest in the breather box but nothing looks chewed up. (Edit)Entire bike is apart now and there's nothing visible in the wiring. Any sensor or anything that could ground out known to cause issues. It doesn't run perfect but will run with the lights on but will do nothing but idle with them off.