Devo,

There could be other things wrong, and as Scott And unlawfull has suggested, cheap or inferior fuel could be the problem. You could test that by adding a small percentage of castor oil to your fuel and see if it will affect your temps. But you can't forget all the other things that could cause a lean air:fuel ratio and overheat your engine. Things like a leak in your crank case back plate, your crank bearings, air leak around the base of the carb, your head shims having debris between them, ven the exhaust gasket. A VERY small air leak will cause this overly lean condition. You just have to take your time and look very carefully at ALL possibilities.

I hope this helps

Oh forgot about the fuel tank not holding pressure will cause the leaning issue..