I would be very surprised if you needed a new motor as they are extremely reliable. Two issues spring to mind. The first is that the drive pulley is superglued to the motor shaft and it has been known for this to become loose over time. The second is the phasing capacitor to the motor which may need replacing. However, there is a good chance it is the first issue. Buy a new belt, clean the drive surfaces put a drop of glue where the drive pulley mates with the motor spindle.