Hi Grumpy, sorry about the time delay,, after x-mas rush is on.
The reason you are not able to see the choke linkage in my photo is i removed the throttle set up so i was able to get a good clear shot of the governor arm for you, and yes my set up is excatly like in the diagram you supplied.
Have done as suggested and held the governor wire with pliers and gave the motor a run.. It will only do this in idle mode. I am not able to open up the throttle to far as it will conk out straight away. Going by the governor arm on the carby it is running in idle mode but to me, just listening to how it runs, it seems to be running to fast as if on half throttle. Would it worth trying the governor in a few different set ups, might snag a winner.