XP Flomaster Pump. The armature shaft turns (although is squeaks a bit). Put the breaker on and all I get is a hum. Someone told me it's possibly a starting capacitor which is located on the motor (bolted on) and that these can be easily replaced.

Assuming you buy into this theory, which of the two covers bolted to the motor is the capacitor? Hint: One is larger than the other.

Thanks!

the advise is sound.

If it's a two speed motor, it will have two capacitors. One may be in the back where the wiring is, but usually there will be a couple cans on the motor. Mark which is which, take em both in, have em both tested at the place you get the new one.

Other possible cause would be a warn bearing, such that when power is applied, it force the rotor to contact the windings and seize the motor.