Today in the middle of mowing my 1 acre, I noticed the transmission getting sluggish, more and more so. I'm 90% done cutting the grass, but it barely moves and I cannot finish mowing with the tractor.
I occasionally tried to disengage the transmission then bleed air by moving the gear shift forward and back several times, but no improvement.
The manual indicates it could be just about anything: too much grass under mower, dirty air filter, dirty oil, faulty spark plug, dirty fuel filter, stale/dirty fuel, water in fuel, loose spark plug wire, dirty/clogged muffler, loose wiring, carb out of adjustment, or engine valves out of adjustment, or motion drive belt.
The engine sounds fine.
Based on experience, can someone point toward a specific issue? Can the transmission itself be shot? The manual didn't show this, but did suggest all of the above possibilities.