Thats weird, cuz my heat problems come from my esc. I can run the 6900 on 2s or even 3s all day and it dont break a sweat. I went to play at a construction site, dropped my gear to 15/90 and the esc didnt take long to hit 200. Let it cool, same thing, so I packed it up for the day so I wouldn't break anything. The whole time, the motor was 145ish. Perhaps I should have went with 13t pinion. That low of gearing gets really torquey jumpin around at every touch of the throttle.