When properly broken in, a motor can achieve a 10% to 20% increase in power over a motor that has not been broken in.
The PN Racing Motor Break in kit includes the motor stand, a slave motor, and pinion gears. Note that the Much-More Motor Master is not included.
Using a slave motor allows the motor to break in without running under its own power (which heats everything up and glazes the bushings, preventing a quick break in). Properly seating the bushings will increase performance by reducing drag. If you run the motor under its own power to break it in, you risk heating and glazing the bushing surface where the armature pole makes contact. A glazed surface will be harder to wear in. When running the motor under its own power arching occurs that may pit the brushes and communicator before the communicator can be properly worn in by the brushes. Using a slave motor will drastically reduce the amount of arching. Note that the only way to remove arching completely on the new motor would be to remove one brush and break each brush in individually.
Most experts agree that a motor should be broken in at 1.5 to 3 volts for 10 mins or more. This can be achieved by connecting to the Much-More Motor Maser, using the motor break in feature of the ICE charger, or simply connecting the slave motor to a single 1.2 AAA cell for 1.5 volts or 2 AAA??s in serial for 3 volts.
Please note that it is important to keep the lead wires separate on the slave motor as well as the break in motor during operation.