Quote Originally Posted by Mikel View Post
IIRC, dieseling can be caused by too little octanage in the fuel, too rich an idle mixture or an idle that is set too high.

Advancing initial timing allows the engine to idle at a lower butterfly opening, reducing the chances of dieseling. You also get quite better throttle response.
Exactly. Running after the switch is turned off is all of the above. Having the timing more advanced is often the culprit. But I have mine too far advanced, monitor it carefully but have a little more power. Not a recommendation, just "what I do". As Mom used to say, "Don't do as I do, do as I tell you!" (Or words to that effect)