You have a safety switch or relay problem. PTO is OK since it will engage when you hold the switch.

Yeah....

Check the Seat Switch, Reverse Switch to make sure the Reverse Relay is being energized.

Thanks Guys !

Turned out to be that one of the leads had come off the side terminal tab on the reverse switch. Appreciate it !

What did you ever come up with for that exhaust nut?
I had the same trouble and had to remove three bolts that hold the controls on and pivot them enough to get an offset box wrench on.

Found a wrench that fit, sort of and got the job done.