I have an Agco-Allis garden tractor with a 20hp Kohler motor. At the end of the season last year, one of the rocker arms came loose and went through the valve cover. I fixed this issue, and put everything back together- the engine would not start. It was backfiring and carrying on, and occasionally would get close to starting. It seemed to me like a timing issue, so I checked for spark on both cylinders and everything seemed to be fine. Long story short: I pulled the motor and found that the keyway on the flywheel had sheared off and spun about 1/4"- essentially throwing the motor out of time. I replaced the keyway, reassembled and reinstalled the motor, and it ran fine. I also replaced the fuel lines and fuel filter, mainly because the fuel line to the crank case was nearly worn through. After mowing with it a few times now, it suddenly lost power whenever I have the PTO engaged. It seems to idle ok, and achieves full RPMs under no load- just not when the PTO is engaged. It will run the deck without stalling, but will not achieve full RPMs. If I watch the fuel filter, I can literally watch it be sucked dry of fuel regardless of engine speed. I thought that the fuel pump could be the culprit, so I replaced it today with no noticeable improvement. My thoughts were governor or head gasket. I believe that the fuel pump is driven off of crankcase vacuum which could be affected by a blown head gasket, right?? This would explain the shortage of fuel and lack of power to the motor. Any insight would be greatly appreciated, as I hate to spend unnecessary time/money trying to diagnose this issue.
20hp Kohler on Allis tractor will not achieve full RPMs with PTO engaged
- Thread starter bshisler
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