Cheers Bob, I did spot the cable positin and thought it was solely an issue with this until I read Jarrods post.
I'm pretty sure now, that it's at the electrical end as I didn't move the cable nut thingy.
So I think I understand, as I pull the lever to the stop position it makes the pins contact and earths out the ignition.
What I don't see is how these pins are moved. I did spot that there was a bit of rotten rubber inside the outer cap and I reckon that was the pin rubber you mention.
I reckon for simplicity I'll run the wires up the air intake and put a pushbutton by the lever.
I think I seized the engine at the weekend anyway, so it's the least of my problems at the moment.
Cheers again
