I have a Fox 50 that is running very hot, it seems to be leaning out, but mixture adjustments really don't affect it that much. It also has a hesitation on throttle up, like a over rich setting, but runs good once at full throttle, but still gets hot. bought this plane with this engine on it and do not know much about it. HELP!!!

Take the carb apart and clean it thouroughly. Sounds like a partially blocked fuel system... possibly an air leak under the carb would aggrivate things, so when you put the carb back on, use a little high temp RTV sealant.

Another possibility is the ancient gasket at the backplate can start leaking. Neve hurts to clean off the old gasket and put in a new one (can be made from newspaper and red RTV... since that's going to be a hard to find part.)

I have a fox 50 that had similar problems, I believe a seal at the front of the engine was bad so i sent it to Fox. They went thru the engine and carb, got it running good and sent it back and only charged for parts, which was less than $40 best I can remember. I suggest send it to them and get it running right.