I have a 1996 cal spa 2000 240v set up. Problem was, I had to replace the sc-20 fuse. when I did, , I cut the power back on, and the pump would cut on and off very quickly at low speeds. Took out the pump and hooked up to 120v. On low, the same thing, but on high speed, seems to work fine. Any ideas? It is a GE 4hp pump. 1-capacitor chamber on top.

Sounds like you have a bad motor.