Our son's little big hauler motor gets extremely hot after running for only about ten minutes. I mean REALLY HOT. Then it stops. Give it a few minutes to cool and you can get another ten minutes. I've taken it out of the chassis, removed the rods, and have it sitting free on a table with clips to the motor leads. Same result. Gears and wheels have been cleaned, greased, oiled. Help. A dad's image is at stake.