need more muscle than 90 inch mowing deck

[radman1]

Using your figures, 21 GPM at 3000, requires 43 HP to run that pump, and when that energy is sent to a hydraulic motor, the motor should be developing about 36 HP with an 85 % efficiency. Does anyone know the cu in displacement on the hyd motor? Long grasses will just about slow down anything, and build up large clumps. Cutting twice may be the answer, or slower rate of travel. Sharp blades also. It would be interesting to put a hyd gage on the motor circuit and see what the pressure is when the motor is stalling. If you don't see max pressure or relief pressure, then the pump is not putting out the pressure, or the motor is bypassing.

I use efficiency of 65% which I think is more realistic. My TC 5610 (56hp) has high flow hydraulics with about 28 gpm to run the rear pto. Used my 6' KK tiller this year on it for the first time. My Jd 3720 (44hp) is rated at 35 pto hp. The TC couldn't come close to matching my JD CUT. I know my hydraulics on the TC are at 3000 psi when measured with gage. I tilled about 2 acres with the TC. The CUT would have done it in half the time.