The brushes in these tail motors are crap... They wear out in no time. If there was an easy way to get the brush back on the (rotor?) part of the motor without damaging them, you could make it work for a little while longer. Perhaps there are other motors of this size that would be more appropriate??? I've seen on other threads here that the motor was designed for 7.4 volts, not 11.2 volts as with the lipo batteries. So the additional voltage burns the brushes that much quicker.

MPB