Front pto electro clutch

[Aardvark]

I have just attached a belly mower to my ancient B5100E and after hooking up the belt to the front mounted pto I find that the electric clutch doesn't seem to bite properly. There's a nice loud clunk when I throw the switch but just not enough oomph to turn the pulley. Everything is free running and there is nothing jammed so I assume the clutch is shot. Before I take it apart for a look is there anything I need to know? Has anyone rebuilt one of these things or is it time to dust off the chequebook?

 

[Rust Addict]

I've only ever hear the clutch "clunk" when the engine is off, never when running. You check the belt tension and maybe the electrical "ground" contract through the bolts into the frame of the tractor?

 

[Aardvark]

Just to update on the clutch problem.
I think Vic is right about it not being a serviceable part.
The problem in my case seems to be that there are three strips of metal that link two sections of pulley together, inner and outer. I think they work like a shock absorber to some extent. These links have snapped off at the ends and it seems they were originally rivetted in place during manufacture. No apparent way to open it up to replace these links. Game Over.