Garrard RC80M running too fast

I'm fine-tuning the '50s Garrard RC80M I recently picked up.

On 33 RPM at least (not sure about the other speeds) it's running a bit fast. I don't have an owner's model for the 80, but the manual for the similar RC88/4 says:



I've identified the motor, but I'm not sure what the governer or armature shaft is. Any help would be appreciated!

FWIW, I've already cleaned the drive wheel and inside rim of the platter.

Do you have any pics? I can't seem to grasp what we
are supposed to be looking at.

Thanks.

I've managed to fix the problem by carefully filing down the motor pulley, while measuring the speed with a strobe. Now it runs at the correct pitch!