Columbia Baby Grand Electric Motor

[Phono-Phan]

I am finally getting some time to go through my Columbia Baby Grand phonograph. It seems that the electric motor is sluggish at times. I have removed the auto start/stop mechanism from the gear train to eliminate that as being the cause. I haven't worked on a combination AC/DC motor before. There is an adjustment arm pictured that has both the DC and AC markings on it. I am looking for some advice as to how this motor should be set up with this adjustment arm. I have oiled the bearings and spindle shaft. It will run strong for awhile and then get a bit sluggish. Is there a way to get more "PEP" out of the motor? I really think if the motor had more power that the auto stop/start mechanism would work properly.

[Phono-Phan]

Thanks to Phonoboy, I was able to get the Columbia motor to work much better. I was able to gain access to the brush and armature area. I used some 600 grit emery cloth and was able to clean off the armature. I then used some degreaser on a Q-Tip to clean up the residue. The motor has more snap to it now. I was also able to get the auto stop/start mechanism to work properly. Next, I will get to re-wiring the chassis and light switches. The old cloth wire is in pretty bad shape.