I'm guessing this is your first gas engine. Setting up the carb is not the same as on a glow engine. You are correct in assuming that the motor is running too hot, but it is the low end needle that you need to adjust. (Are you sure you have enough air going over the engine and a large exit hole? This is a very common mistake with first timers) This could be one of the reasons your engine is so hard to start when it is hot. Adjusting the low end needle will effect the high end, but always set the low end needle first. I have to say that even I found it a little difficult to re-start my engine straight after a long flight. Other than that I have had over 2 years of experience of running a BME 44 in the heat of the dessert with very few problems.