I tried this and believe the motor starts without a load and doesn't trip the breaker. The pump is down near the shore of the lake. The timer and breaker are in a closet in my basement. I reinstalled the pump without connecting it to the load (irrigation pipes). I turned it on from inside the closet. Quickly walked outside. Heard the pump running. Saw a wisp of smoke from a distance so I ran back inside and killed power. It only ran for a few seconds. I am concerned I was burning up the impeller, but hope it wasn't damaged in those few seconds. Of course, the smoke may also have been from the motor. It's 15 years old and I guess the windings may be shot.

I think I will try to examine the centrifugal switch you mention. Sounds like a simple yet ingenious set-up. If I can't isolate a problem there, I will try to test the capacitors. If that's not the culprit, I need professional help.

Thanks for your informative response.