Yamaha Lower Unit Assy - 6G1-45300-13-4D. The Yamaha Lower Unit Assy - 6G1-45300-13-4D is engineered to provide outstanding performance and reliability for your Yamaha outboard motor. This lower unit assembly ensures a perfect fit and optimal functionality, significantly enhancing the overall efficiency of your marine engine. Constructed from premium materials, it is designed to withstand the harshest marine conditions, offering exceptional durability and consistent performance.. With the Yamaha Lower Unit Assy - 6G1-45300-13-4D, you can experience smooth and efficient power transmission that minimizes drag and maximizes thrust. This results in 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, delivering a reliable and enjoyable boating experience.. This product has been superseded by: 6M8-G5300-11-4D. 6G1-45300-13-4D - LOWER UNIT ASSY