I thought about fitting a heat sink on it but their is no room for one. I think it's just overgeared. I put my 10x2 back in with the same gearing, springs, and brush's and it didn't get nearly has hot as the 7x2 did. Once my other gears get here i'm gonna put it back in and see whats up.I just don't want to severely damage the motor by overheating it.