After sitting for several months, my 115v diesel pump would hum but not run when turned on. I took the lemon shaped end plate off, removed the fiber key that holds the rotor to the motor drive shaft, put a screwdriver in the motor drive shape and gave it a turn. I then replaced the plate and tested the motor. Took 5 minutes. It ran fine.
Quick and cheap fix. The rebuild kit costs hundreds of dollars and doesn't address that part and a new pump costs $500 or more.
