I had to replace a broken drive belt on the lathe. Now it has a hard time increasing speed. I can increase it by turning the shaft that makes the pulley move with a wrench while its running. It turns easy. I can slow it down with the button on the headstock but when I increase it goes real slow than stops. I removes the small DC motor that is supposed to move the pulley to change the speed and it runs fine with no load. I was wondering if the motor is just weak and needs to be replaced. South bend does not have it or know anything about it.