I have a 5211 that is only getting fuel to the rear cylinder I can get it to run with a little starting fluid but have no throttle response at all. Only stays running at high rpm. Removed lines where they enter the cylinders but am getting nothing in the front two Not sure if the injector pump is bad. Or clogged or something stuck closed or what. Looking at the exploded view of parts inside pump assured me I shouldnt mess with it myself. Just looking for advice or knowledge as there are no dealerships service centers within 200 miles of me