Is it beyond repair?
It is beyond economically justifiable repair.
However, if the commutator is able to be cleaned up without going all the way through the segments the windings may be replaced.
The repair-ability of the commutator will depend on the construction of the commutator.
A shop will probably decline to accept the motor, but it is a doable do-it-yourself project.
Remove the windings.
Carefully note the position, number of turns and polarity connections of each individual winding.
A repair shop may help you with the proper gauge replacement wire and the fish paper and shims needed.
Good luck.
Is it burned out?
It doesn't look good.
However, it will need to be tested to determine if it is burned out.
First check the resistance from the armature windings to the iron core.
If the windings are shorted to the core,it is burned out.
Next check for winding turn to turn shorts.
The test for that is a growler.
A shop may do a growler test for you.
Don't have a growler?
Improvise.
This is a test that I devised to do growler tests on generator exciters, in place.
Assemble the motor.
Remove the connection(s) between the armature and the field.
Apply 120 Volts AC to the field.
You should see zero volts at the brushes and maximum voltage from opposing commutator segments at 90 to the brushes.
Turn the armature one commutator segment at a time and recheck for zero and maximum volts.
Any deviation from zero and maximum indicates turn to turn shorts.
In the event that the armature is completely and totally shorted out, it will start to heat up and you won't see any voltage at 90 degrees to the brushes.
