Yamaha Lower Unit Assy - 6FN-45300-01-NA. The Yamaha Lower Unit Assy - 6FN-45300-01-NA is designed to deliver top-notch performance and reliability for your Yamaha outboard motor. This lower unit assembly ensures a precise fit and optimal operation, enhancing the overall efficiency of your marine engine. Constructed from high-quality materials, it is built to endure harsh marine conditions, offering exceptional durability and consistent performance.. Experience smooth and efficient power transmission with the Yamaha Lower Unit Assy - 6FN-45300-01-NA, which minimizes drag and maximizes thrust. This leads to improved 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, providing a reliable and enjoyable boating experience.. This product has been superseded by: 6FN-45300-03-NA. 6FN-45300-01-NA - LOWER UNIT ASSY