If you have a perfict heat on the glow plug the mixture is actually leaner and you don't get much smoke, and very little at midrange to idle. Sometimes you can adjust midrange mixture by raising or lowering the tank a bit, but not by much and it won't work for some carbs. But if you have a clean transition and it is not detonating, I would not worry about how hot our engines are. If you were to run it on the correct mixture of gas it would run even hotter with no running problems, so they tolerate the heat very well. Just as long as you have good oil of at least 20% that is.