When accelerating there is a noticeable rattling from the starboard side of engine compartment. Starts at about 1200 - 1500 rpm and stops when the boat planes. There is no noise at idle as well as no noise when steering is turned either all the way right or left when idling or under way. Before I haul and have the outdrive removed to check gimbal etc. could it be the motor mounts or is most likely the gimbal bearing and or u joints?