Yamaha Lower Unit Assy - 6FN-45300-12-NA. The Yamaha Lower Unit Assy - 6FN-45300-12-NA is engineered to provide outstanding performance and reliability for your Yamaha outboard motor. This lower unit assembly ensures a precise fit and optimal functionality, enhancing the overall efficiency of your marine engine. Made from high-quality materials, it is designed to withstand tough marine conditions, offering long-lasting durability and consistent performance.. With the Yamaha Lower Unit Assy - 6FN-45300-12-NA, experience smooth and efficient power transmission that minimizes drag and maximizes thrust. This results in better fuel economy and a smoother ride on the water. Trust in Yamaha's commitment to quality and innovation with this lower unit assembly, ensuring your boat operates at its peak in all conditions, delivering a reliable and enjoyable boating experience.. This product has been superseded by: 6FN-45300-13-NA. 6FN-45300-12-NA - LOWER UNIT ASSY