Gravely Promaster PM360 Kawasaki FD661D engine trouble
just grabbed a Gravely Promaster mower, built around 1998-99. Looks complete, looks well taken care of, but won’t start or stay running when it does. Has a Kawasaki FD661D 22hp engine. Compression tests at 150-155psi each cylinder. Carb was taken apart and cleaned, no problems there. The fuel shut off is missing, so that’s not it. Seems to have good spark. Valves were a little out of spec, but are now .25mm.
What happens is, when I try to start it, it acts like the battery is very weak. I put a known good battery on it and it still does this. It acts like a 6v system. Cranks fast and then slows down, cranks fast and then slows down. Sometimes is does start, back fires out of the carb and then stops. Maybe will restart. Choke makes no difference and throttle makes no difference. Has plenty of oil, not overfilled.
I have hooked a jump box right to the starter and I still have the same issue. If I pull the plugs, cranks non-stop no problem. What concerns me, is when the engine stops after running for about 10 seconds, it STOPS. It doesn't peter out, it just STOPS like something mechanical is stopping it. I initially thought the valves were out of adjustment, sounded kinda like a valve was sticking/staying open when it shouldn't have been.
Is there something I am missing with these units that I should dig into before I pull the engine to rebuild? Is it worth rebuilding?