When you shut the key off, the spark and the fuel should shut off, no fuel, no run.So I guess I'm gonna answer my own thread here. After looking around, I've found that apparently dieseling is caused by several things, but basically it is the air/fuel in the cyl. igniting after the spark has been shut off. One cause of this could be carbon buildup, another one I found was the wrong spark plugs. Apparently there are cleaning solutions for the carbon buildup. Hope this helps someone.