MM is way too hot! Why?

[Xtremespeed]

Would the motor not run hot if it was overgeared that bad? I built this car for bashing and don't really have much interest in gearing way down as I don't have to drive real technical like on a track. I actually have some larger pinions I would like to try, but I think several people have run the 1.5d with 13-14/46 and had good results. I'm more into the wow factor I guess. Anyways, I've tried running it outside, and it's the same, just thought I would try some short bursts in the house to see what happened. I understand speed runs will heat everything up with my larger pinions, but could I get away with the 14/46 with another controller maybe?