By adding some rubber, plastic or wood to the backside of the removable motor mount, this will correspondingly move the motor farther away from the hull. My motor mount has a block of wood on the front side, with a thin layer of rubber on the back side. If you add a half inch of rubber to the backside, it should move the motor a half inch away from the hull. Also, consider that your motor may be missing a stop block/tilt adjustment...as the prop thrusts the boat forward, it may be pushing the shaft forward; having a stop block/tilt adjustment on the motor will prevent the shaft from moving forward beyond a certain point.