theclosetguy wrote:I quit. Mike M
You are not really going to quit after all the time you put into it, might as well persevere.
Seeing as the motor is an AC synchronous, it should not slow down unless the voltage dropped or some mechanical drag impeded it. Could it be that there is some play in the motor's bearings and the spindle is contacting the side too much? Is the speed constant, albeit slow, and are you sure someone before you hasn't sanded the pulley?
I would try checking the motor's bearings, maybe clean a relube with thinner oil, or if there's play try a thicker one. If that fails I would try getting a new motor, a Premotec might work depending on the spindle's diameter. It would need to accept the old pulley.