I forgot to mention about my experience with ignition timing. As some of the other posters mentioned something about timing and mixture. Retarded timing can cause all sorts of problems including: poor performance, poor gas mileage and the engine may run hotter than normal. Maybe quite a bit hotter than normal. And a continuing buildup of heat even at idle. (DAMHIK) Doesn't hurt to check your timing.

As one of the other posters remarked, running lean can cause an increase in operation temperature. If it's this lean you will probably also notice knocking from detonation. PROBABLY but maybe not.

Karl M.