Motor Started Smoking

[Pauly]

I just changed out the ESC with a ZTW 45A from the factory 40a ESC on St Model Acrobat and when ground testing it ran up like it should, but started to smoke at motor. The main reason I changed the ESC is because of a previous crash with the model due to a signal loss. There was really very little damage to the plane except for dirt in the nose. I removed the motor and cleaned and sprayed with electronic cleaner. It then would not run up or have a enough power to come off he ground. My question is what would cause it to smoke from motor? It seems to have the RPMs still, but did blacken some of the wires inside motor and seems to stop after running it up.

[F22trainer]

Bearings, shaft and or armature/ windings. I would also check the rear bearing - one of mine slipped about 1/4” and when the motor would run up it would separate from the housing under prop load.