Etek R trouble shooting?

I have a brushed, 2nd gen Etek R on my electric motorcycle, with a LiFePO4 48V 20A pack. The charger timer died and overcharged the pack and melted it down, on top of the Motor (HIGH Temps!). We have a new / used LiFePO4 48V 20A pack now, and have had the AllTrex controller factory Checked (OK). I suspect that there is something wrong with the motor, though I replaced the brushes. It just doesn't have much power, and when full power is applied under full load, it groans. Could the meltdown temps have de-magnetized the motor? Is it trash? I have checked the amp draw under load and am seeing adequate amperage (max running = 55A, momentary peaking at 100A). Are there any other basic trouble shooting tests I can do? Where can I send this motor for test, service repair, etc? (The dealer can't do this - only wants to sell me a new one).
Thanks!

Your best bet would be to contact the manufacturer, Mars Electric LLC. This motor isn't really an Etek, it's really one of these: http://www.marselectricllc.com/me07081.html re-badged by the retailer you purchased it from. The guy that runs Mars Electric designed the motor and in my experience of dealing with him seems helpful enough. His name is John Fiorenza and was involved with the design of the original Briggs and Stratton Eteks I believe.

Jeremy