Backfire is usually when the plug doesn' tfire then does. First check yoru ignition, meaning dwell(ppoint gap) timing, and then check compression. Also if you know what side is backfiring pull the valve cover off and see if all the valves are working well. You may have a bent pushrod on the exaust and not allowing the valve to ope all the way.
Wednesday, August 4th, 2010 AT 8:35 PM