I'd start with the safety switches like the one under the seat. Jumper across the wires and see what happens. I just bought one myself so I don't know what other safety switches are on it. I know if you hit the brake pedal it will disengage so I assume there is another switch in there somewhere.

Does it bog down and stall indicating mechanical issue underneath or just immediately die like you raised up off the seat? Not familiar with that machine, but typically, you have a switch on the brake, seat, and PTO, inspect wirinig and ensure all are plugged in properly.

Didn't finish first comment, apologies.

It just quit when mowing - now it blows 15amp (switch fuse) and engine quits running as soon as PTO engaged.

Have checked seat switch, am now in process of full service to see if anything comes to light.

Any suggestions still welcome.

Andy

When a fuse blows you've got a short to ground or a "load" e.g. PTO solenoid shorted. Check for pinched wires, etc. Meter will make life much easier, as will a schematic.