I would suspect the insulating coating on the motor's stator windings would be melted by the fire. I don't know of a way for you to use an ohmmeter to test the integrity of the motor, but I'd put in a new capacitor and try.

The capacitor is needed to give the motor enough torque to start it to rotate. An internal switch takes it out of the circuit once it has gotten to about 80% of its operating speed.

BTW, if you do try to run it, I'd recommend doing it outside in case it shorts out and generates a bit of smoke before tripping the breaker switch on that circuit.

For testing purposes you might be able to to get it to run without the cap if you just spin the shaft by hand once power is applied. Small motor caps are dirt cheap however (less than $5 usually).

Motor windings however should read a dead DC short. You likely have problems. The first thing I would do is look at the brushes. They or what they contact may be failing. You can also verify the continuity of the wire between the brush and the power terminals.

Often you can find a small motor shop that can do these rudimentary tests for you and if they find the motor isn't repairable (or worth repairing) offer you a replacement at reasonable cost.

Call me neurotic, but I would also worry about potential shock hazard if you did get it running...

I have tried running the grinder I have even spun the wheel while turning it on so far it has done nothing

Probably a open or shorted winding (given your previous observations probably open). Take it to a motor guy.