Hi Max.
Yeah. Did that. It's a 1-1/8" socket.
I've got the flywheel off.
I have to take the motor off the mower to get to the crankcase BUGGER!
The last thing I want to do is replace the camshaft. I probably couldn't get one anyway!
Thanks for you help and suggestions mate.
I'll post my results when it's sorted.

Cheers

Rob