Yamaha Lower Unit Assembly - 60 & 70 HP 2-Stroke Models - 6H3-45300-20-8DYamaha Lower Unit Assembly 60 70 HP Complete Drivetrain Assembly 6H3 45300 20 8D Overview The Yamaha Lower Unit Assembly 60 70 HP 6H3 45300 20 8D is what takes all that engine power and actually puts it to work in the water. When a lower unit starts going bad, youll feel it right awaynoise, vibration, or loss of push at the prop. Instead of tearing into gears and chasing problems, swapping the full assembly is usually the cleanest fix. It gives you a