[Silent_NightR34]

this was taking from minizworld.com so don't give me all the credit...

Breaking in a new motor (or new brushes)

Right then :-) Get yourself a glass of water, an aaa battery box with two batteries in it, some sticky tape, a little bearing oil, and some motor spray.

Submerge the motor in the water, and tape the wires to the side of the glass so that the motor is freely suspended, not touching the sides. Connect the motor to the battery box such that it spins the same way that it will in the mini Z. Leave it running for 5 minutes or so (the water usually turns dark gray), remove the power, take the motor out of the water, spray liberally with motor spray, leave to dry for 20 minutes, oil the bearings, then put it in your Z - eh Viola! :-)

Why use water? It provides a load whilst running in, it removes air, so prevents a lot of the arcing between the comm and brushes, and finally it keeps the motor cool under load.

Generally, with the water method, most people run in their motors at about half their normal running voltage - So, we run our with four AAAs normally, so run it in with 2 AAAs.

This tip provided by Rob D. in the UK.