We have this mower since the early '90s when it was new. It is older, but has worked well & has 247hrs on it. It has been sitting for a few years due to this problem. It has the Kohler Command 14 twin engine, Hydro Gear BDU-10L pump/motor, and Hydro Gear gear boxes.
On to the problem. The engine starts/runs excellent, but seems to lack sufficient power to turn wheels and blades at the same time. It will run the blades by themselves all day long without breaking a sweat. It will run the wheels by themselves, but it definately pulls the engine down. Even if it is not moving, just having the brake off and the wheels not turning, it will pull the engine down. Run both the blades and the wheels, and it will pull it down to the point that it will die. The govenor does work, but it doesn't keep up. We have done extensive tune up on the engine. New plugs, wires, coil, fuel pump, carb cleaning/adjusting per manual. Valves are in tolerance, compression is good.
Drive belts are not the best of shape, but are tight and not slipping. Everything is adjusted properly per manual on the drive system. I am left thinking there is a problem with one or both of the pump/motors. The wheel will turn with the bypass valve depressed, but it does turn quite hard. I have noticed that the return oil from one of the pumps fluctuates while the other pump is a steady stream. Almost like it may be cavitating.
About out of ideas here, so if you got some, let them fly. I hate to put her out to pasture, but it's worthless if it won't work.
The only thing I could think of thst is common to Both pumps is The Hydraulic Oil...
If One or Both of the pumps are not damaged an oil change "May" be worth trying.
Also give the Bypass valve a close look, is it restricting the 'Normal' flow path when in the drive position...
Has the mower been pushed or towed while the bypass valves were not placed in bypass?
Your problem seems to me, to be a hydraulic problem rather than an engine problem... UNLESS the engine is running on One cylinder instead of Both.
Next time its running engage the blades and deliberately kill one cylinder's ignition & then do the other... if you find one side makes little or no difference That will be the problem. :smile:KennyV
I believe the bypass is working. At least I can't turn the wheel without it depressed. I can't say with absolute certainty that is has never been pushed or towed, but I don't think so. Also thought of taking one belt off a hydro to see if that would change anything. Should tell me which hydro is a problem. Good idea on shutting down one cylinder. I'll try that first. Thanks for the ideas.
