RE: BME 50 gas/oil mixture
Doesn't matter what engine you are flying, I would personally stay away form the 100:1 ratios. More oil=more power and protection from all the reports I have read. Find a good quality oil (synt or non-synt) that is recommended by the manufacturer to be mixed in the range of 32-50 to 1
Over heating usually comes from incorrect adjusted needles and/or poor cooling.