Well my higher than expected engine temperatures are probably not what everyone else will measure. I feel that the temperature range as mentioned by Pe Reivers is about what people should expect. But the engines with the short fins on them that look like glow engines will run much more hot though.

Doing this with a small 9cc engine is probably over the top. But it does run pretty good though. Plus flying it a lot here in the hot summer Texas weather doesn't help matters much either. But it is cooling off now with summer ending. You do not need to put a Walbro carb on this brand engine, it was an experiment I was conducting.

I think this type of engine needs more cooling fins on it. I have seen others using different brand engines like this glow engine conversion having higher running temperatures too.