Hi Norm, thanks for the welcome and the reply.
I did have a minute to look at the mower this afternoon and checked a couple of things.
I took the top cowl/cover off the engine because I wanted to check the ignition lead but while the cover was off I engaged the cutter blades and turned the engine over by hand with the flywheel/cooling fan on the top of the engine. It seemed to turn over freely so I think the belt pulleys are OK.
I haven't had it running again yet though to check the governor arm as you also suggested. I did remove the spark plug to have a look at the colour of the electrode, it didn't look overly dark and sooty or whitish so I guess the mixture isn't too bad.
While I had the plug lead off I checked the resistance of the lead from the magneto to the plug end of the lead. The resistance of the ignition lead conductor from the plug end to the magneto was only about 1.5 ohms so that was fine but when I tested from the stainless crimp that connects to the plug the resistance for the entire lead was in the meg ohms and the crimp itself looks very corroded and ordinary. I don't know that the ignition lead is my problem but it's certainly something that needs to be rectified.
My plan is to re-terminate the spark plug end of the ignition lead when I get a new crimp, once I've done that I'll run the engine again and then I'll try your suggestion about the governor arm.
Thanks for the help.
Andrew.
