Small Engine Problems? Ask an Engine Mechanic for Answers ASAP
Much more likely a bearing in one end of the motor is trying to lock up. Only two bearings in the motor, front and rear. The front one takes all the load, and if it is going out, it can spin freely and then try to lock up. With saw unplugged,turn blade by hand in both directions feeling for rough spots. It will not have anything to do with the capacitor.