can anyone tell me whether or not these little engines run extremely hot? The sled had a previous owner and the govenor looks like it may have been modified.Don't like what I saw for spark plug color so I tried a cooler plug. The air filter is clean. I will check to see if it has proper jet in the carb.Any comments greatly appreciated.

Sounds like your on the right track, also could be a partially plugged carb leaning it out, possibley no stabalizer when stored??? If its running that lean at these temps theres no way it'll stand the colder weather. A little investigation time should answer your question.
:)
Rick.

Clean the Carb! Chances are the main jet is cloged, old fuel, residu on the walls, etc. I would just put a new main in it. They are cheap. make sure your air cleaner is clean and clear.

I believe the cooling fan is intergrated in with magneto, so no belts to wear out. But I can be totally sure, havn't fix one of those in years.

Those engines are bullet proof. They are actually a generator engine.