What (besides heat) can demagnetize a motor?

[suicideneil]

Well, I was always of the impression that they were 6 pole motors, until someone contacted me about their BM that was being repaired- they are indeed 4 pole motors.

As for de-maging the rotor, only heat couod do that, or a poweful electromagnet wrapped around the motor for a long time.

And it is the rotor/magnet that has the poles 2-4-6 etc, the windings just determine the kv rating.