This is 24v AC motor. I checked the connection and got 24v AC I tore the motor apart and it is a brushless induction motor.
I figured out by timing the motor in my working machine that the motor is 500 RPM's I counted the teeth on all the gears and figured the RPM by that. I think the 21 v if it's AC would be OK but motor would be a little less powerful. I think these are much more powerful than they need be. I'll look into that microwave motor. Thanks info Tim