Yamaha - Water Tube Cooling System Component 6D8-44361-30-00. Overview. The Yamaha Water Tube 6D8-44361-30-00 is a vital part of the cooling system, responsible for carrying water from the lower unit up into the engine. This steady flow of water is essential for regulating engine temperature and preventing overheating. If the tube becomes clogged, bent, or damaged, it can restrict water flow and reduce cooling efficiency. Replacing it helps ensure your engine stays properly cooled and performs reliably on the water.. Key Features. • Direct Cooling Water Transfer - Moves water efficiently from the pump to the engine.. • OEM Fit Precision - Built to Yamaha specifications for proper alignment and secure installation.. • Maintains Cooling Efficiency - Supports consistent water flow to prevent overheating.. • Durable Construction - Designed to withstand heat, pressure, and harsh marine conditions.. Engine & Boat Compatibility. Verify compatibility with your specific Yamaha engine model and