Does anyone know how to time a PMG 132?

Timing is changed by rotating the brush holders with respect to the magnets. I haven't seen a Perm 132 up close, so I'm not sure how the brush plate goes on. Typically, the bolts holding the end bell can be loosened and the brushes can be rotated slightly either way. On some motors, the bolt holes might need to be elongated to accomodate adjsutment.

Then it's a matter of finding the right setting. I prefer hooking up a motor to 12v with an ammeter and adjusting the timing for the minimum current draw. This will be fairly close to neutral timing. Rotating the brushes opposite the direction of the shaft rotation will advance the timing. If you want maximum horsepower, the brushes should be slightly advanced. I wouldn't recommend more than a few degrees from neutral. For best low speed efficiency, neutral is best.