Deere F725 Oil Pressure Warning

[lute]

I've got an F725 mower with a Kawasaki F590V engine; 750 hours on it.
The other day I mowed for about 20 minutes and the oil pressure warning light came on. First time that ever happened. Thought it might be a faulty pressure sensor.
Put a gauge on it and it starts cold with 60 psi, after warmup goes to 52. But then after about 15 minutes of mowing it's down to 36 at which point I shut it down.
Oil and filter are new, Mobil1 10W-30 which may be too light for our 80 degree days here.
I compression tested the cylinders and both are over 170 psi and the motor doesn't smoke or burn oil.
Any thoughts on why the oil pressure is dropping?

 

[clinebarger]

Have you pulled the shrouds on the engine to check for debris build up? The engine could be getting hot.

 

[steve20]

the pressure drops you are seeing are normal after the engine oil temps increase. If you have an oil pressure gauge in a car or truck you would see the same thing. My Corvette starts off at 65-70 psi cold idle, and warm idle is about 25-30 psi.
Possible faulty wiring (chafed wire) in oil pressure circuit causing it to short and turn the oil pressure light on?

 

[doitmyself]

Probably not related to your problem, but just a heads up. The water pumps on those mower engines are prone to go bad. And, while they have it apart, have them replace the plastic camshaft.

 

[Realtech214]

The camshaft gear is plastic, poor design. Throw some 15w40 in that Kawasaki I use it in my OPE with great results. M1 is overkill for sure in that baby!