By pass the switch and see if it engages. Just don't have your toes under the deck when you do this. By pass the seat switch and the clutch switch and you shouldn't need it running to do this, I don't think. I'm not familiar with your brand so I could be wrong, like the weatherguessers.
Mr mow it all:
I am having problems with my email so I'll post here in case you don't recieve them. I have 2 electric pto clutches in stock and they are both from Scag mowers. The one for sale is from a wb 61" deck and I think they are basically all the same. We have interchanged with no problem.
The part is a Warner Electric # 5215-99
Pulley # is 2846
Shaft arbor hole is 1"
Used about 150 hours. Nothing wrong with it.
Check with your Scag dealer to see if it will work. The last time I bought a new one it was $160.00. $475 plus labor sounds real high.
You could have a switch problem. Just turn the key into the on position and short out the pto switch. You should here a strong click. No need to start the mower to do this.
If you get a "click" then replace the switch. If not, make sure that the wiring is good from the switch down to the clutch.
lol homer..... sounds firmiliar! When i had my gravely 3 wheeler i went to go over a small curb and the entire clutch fell off.... im not happy when equipment goes down in the middle of the day but this time... i had to laugh.