Shallow well pump seizing

I have a shallow well pump, convertible jet, on a sandpoint at the cottage. After sitting for the week unused it sometimes seizes, just sits buzzing, at which point I quickly turn the power off. I can turn the motor manually using a screwdriver to rotate the fan through the ventilation holes in the housing, obviously with the breaker OFF. It feels a bit stiff at first but after a couple of rotations frees up somewhat. When I turn the breaker back on the pump will start and then continue to run flawlessly while we are there. Any ideas what may be causing this? Should I dismantle and clean the pump or is it probably time for a new one?

are thair any greese fittings or try a shot of wd-40 on the shaft ends of the motor

It's the minerals in the pump making the impeller and diffuser act like they are almost one. By turning the motor manually, you are loosening the minerals up enough to let it start. Your motor may be a capacitor run motor instead of a cap start motor. They have less starting torque but are actually a better motor.

If the inside of your pump is that gunked up, a new pump wouldn't be a bad idea.

bob...