PTO CONTROLS. How do you engage and disengage PTO.

I don't know but I would guess it could be for a differential lock or to engage the PTO (power take-off).

Zero turn mowers in general require the following.

1. PTO off.
2. Steering levers to neutral position.
3. Parking brake engaged.

A good habit to learn is; When a zero turn won't crank, cycle all the start engine interlocks. Move park lever off/on, steering levers out/in, PTO on/off.

And a simple basic electrical check is; With key in run position (engine not running), you should hear the electric clutch engage/disengage when PTO switch moved ON/OFF.

To engage or disengage the drive motors: 1. Locate the manual freewheel levers at the front of the chair. See figure 5. 2. Push the levers down to engage the drive motors (drive mode). See figure 8. 3. Pull the levers upward to disengage the drive motors (freewheel mode). See figure 9.
If a lever is difficult to move in either direction, rock your power chair back and forth slightly. The lever should then move to the desired position Manual link below.
https://www.pridemobility.com/pdf/owners_manuals/us_jazzy/us_jazzy_select_7_om.pdf

Sad to say it may have never been a bad pto clutch but probably safety switch problem. The running tractor wants you in the seat, brake off, levers over your lap and not backing up for the PTO to stay engaged . There is two push button switches on each lever that lay over your lap ,one on the parking brake,one under the seat. All of these switch wires meet at the PTO switch and all have to agree they are in the position they need to be in to allow electricity to come down the wire to the PTO Clutch.

Replacement of the PTO should solve the problem as these do corrode internally and stick.

Maybe the problem wasn't the PTO switch. My Cub Cadet RZT PTO would disengage when I backed up and then failed to re-engage. I was able to isolate my problem to the safety switches at the base of the steering levers. I sprayed them with WD40 and they've been fine. Just a thought and worth checking. I hope this helps.

Does this only happen when the engine is warm or at operating temperature or all the time even when cold? In older engines, a 'bad ignition coil' would fail when the engine warmed up and would not start again until cool or at ambient temperature.

you have a shortage or your clutch is going bad

I hope this will help you...under the side panels on each side of the mower, there are "reverse lockout safety switches", they are supposed to stop the blades when both handles are pulled back. If one or both of the switches are out, the deck will not engage. Also, under the right side panel (when sitting on seat) there should be 3 relay switches, the one closest to the motor controls the PTO., if this is out, the PTO will not engage.

its actually the clutch not disengaging enough for pto to engage or the teath are worn down on pto shaft