EARLY IN THE SHIF, EE HAD POURED 2 OZ. OF SOLVENT INTO 4 EXHAUST PORTS FOR THE PURPOSE OF DETERMINING IF THE VALVES WERE BENT ON THE WATER TRUCK WHICH WAS LOCATED IN THE EAST BAY OF THE REPAIR SHOP AT COLUMBIA MINE. APPROX. 1530 HE WAS SITTING ON THE RT. FRONT FEND OF THE TRUCK REPLACING THE CYLINDER HEAD. HE ASKED COWORKER TO START THE TRUCK. WHEN STARTED FLAMES HOT FROM THE EXHAU