Any chance that the angle between the brushes and the field got
changed on reassembly?
[John Larkin]

Actually, yes. The rear casing of the motor that contains the brush holder
can be mounted to the main motor frame (containing the field) at 90 degree
increments. So 4 possibilities.

I reassembled the motor as I thought it was originally configured but the
possibility that it's incorrect is large.

I'll try other orientations tomorrow.

Thanks John!

Dave