[A RC Dude]

The fan was designed to clip on and off often for running in water. My MMM 1 fan occupationally cut on last summer but my MMM2 have never gotten that hot without the fan on it. The MMM1 had the fan casing going around the heat sink and blocking a lot of airflow in my mind, the MMM2 doesn't once you take the fan off so it should run cooler than the old one if it's fan never came on. You could always run it carefully for a few runs checking temps to make sure, but you should be fine without the fan since heat was never a problem on the old one.