ORIGINAL: Slo-V Flyer

If a motor is heating up, it means it is overloaded and either you use a smaller pinion, and or larger spur, or you replace it with a lower Kv motor, or maybe if you're way off base, a larger motor. So yes, 90% of the time if your motor is overheating, you want to try a smaller pinion (2-3 teeth lower and test again every 5-6 minutes). SOMETIMES if you gear the motor way too low (too small of a pinion etc) it can heat up also, due to excessive RPMs and other technical reasons, but this is not as common.