Hi Bruce. Thank you for your reply.

The mower is a Power Torque one.

It isnt (wasnt) blowing any smoke.

I dont take the starter off<<?? My mower starts via putting throttle on 'start, turning fuel on, priming it then pulling cord, ..... then moving throttle to 'run. When I rewind the rope I just take the plastic protective cover off the mower, rewind rope and replace plastic cover, and that is all.

No extra movement in the blade disc.

Cheers and thanks. Jay