On Wednesday, October 21, 2015 at 4:52:53 PM UTC-4, wrote:

Just replaced a "run capacitor on my 5 H.P. Champion compressor that was having a similar issue...All is well now.

Yes!

This will very most likely be the problem. The motor is an AC induction motor, no brushes. But the run capacitor is critical to proper torque. And, if you are already in there and the happens to be a start-cap, do that one too.

Peter Wieck
Melrose Park, PA