997. A single-phase capacitor-start induction motor starts, comes up to about 75% rated speed, slows down to a lower speed, and accelerates again. Where is the problem most likely to be?

The motor's behavior indicates a problem with the running winding. After the centrifugal switch disconnects the starting circuit, the motor slows, then accelerates when the starting circuit re-engages, suggesting insufficient torque from the running winding alone. This pattern points to a weakness or fault within the running winding itself, as issues with the starting winding, capacitor, or centrifugal switch would typically manifest during startup.