Thanks for the post!

This could be happening for a number of reasons.

First, if the ambient temperature is a bit cold you can try switching out the Pump oil to a 20W compressor oil as the thinner viscosity will help it start and run easier.

Second, make sure your Belt isn't too loose or too tight, you want about 1/2" deflection when you press down on it; also make sure the Pump flywheel is aligned with the Motor pulley.

Third, you could have defective/sticking Reed Valves in the pump head, or debris that's blocking airflow from the head to the tank.

I'll see if I can glean additional information from the factory rep and post it here.

- MTR

Also, check the current from the outlet to the Motor to make sure you're getting a good electrical current. Then, test the motor Capacitors as either the Run or Start Capacitor could be losing "juice" and causing the problem. If you don't have a Capacitor tester you can use a simple Voltmeter.

Find out how to test a capacitor here:

At this point, then, I would certainly test for current/continuity between the outlet, motor and pressure switch.
There's a good change your Run and/or Start Capacitors are bad, so I'd probably test them first.

- MTR