Yamaha Lower Unit Assy - 6FM-45300-12-8D. The Yamaha Lower Unit Assy - 6FM-45300-12-8D is designed to deliver unparalleled performance and reliability for your Yamaha outboard motor. This lower unit assembly guarantees a perfect fit and optimal functionality, significantly enhancing the overall efficiency of your marine engine. Constructed with high-quality materials, it is built to endure the toughest marine conditions, ensuring long-lasting durability and consistent performance.. With the Yamaha Lower Unit Assy - 6FM-45300-12-8D, enjoy smooth and efficient power transmission, minimizing drag and maximizing 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, providing you with a reliable and enjoyable boating experience.. 6FM-45300-12-8D - LOWER UNIT ASSY