Yamaha Lower Unit Assembly 61B-45300-31-4D - Boost your outboard motor's efficiency with this genuine Yamaha lower unit assembly. Precision-engineered and constructed from premium materials, this assembly ensures outstanding durability and reliability in a variety of marine environments. Its robust build provides excellent resistance to wear and corrosion, ensuring your motor operates smoothly for longer periods.. The Yamaha Lower Unit Assembly 61B-45300-31-4D enhances your vessel's performance with efficient power transfer and superior stability. Perfect for both professional and recreational boaters, this assembly maintains your outboard motor's peak performance. Trust in Yamaha's dedication to quality and innovation to keep your marine engine in optimal condition, offering you a dependable and exceptional boating experience every time you venture out on the water.. This product has been superseded by: 61B-45300-31-8D. 61B-45300-31-4D - LOWER UNIT ASSY