can you do a picture?
I am thinking the motor in that loco is found a few other locos.
buuuut you have to re-configure the motor.
pull a worm and press pieces...
most times the brushes are worn or the commutators are clogged.
If the motor from motorman is 100 percent drop in then you should use that.
I think you will find worm pulling is required fro a motor swap.
victor