Here's some pics. It's difficult to explain the lug in words
In the first pic, item 11 is the plug. Just below the stop lever axis.
The second pic is a view of the IP from the rear showing the lug on that propeller thing. You can guess what you would feel if you poked through the hole with a wire depending on the position of the propeller thing. Note that the IP like the cam turns at half crank speed.
Sixto
93 300SD