Clinton, just checking the air motor for dirt and cleaning almost
never fixes the problem.  You didn't talk about doing any of the
tests that I suggested in my post on MMD 2011.12.11.  Did you try
the test of closing the air line off with your thumb and turning
the motor backward?

As for the Tempo regulator, is the spring still attached to it?
If this spring is missing, the vacuum going to the motor will be
next to nothing.  Another issue would be that the cloth has a hole
or is leaking.

Pete Knobloch
Tempe, Arizona