Yamaha - Water Tube Cooling System Water Delivery 6E5-44361-20-00. Overview. Water tubes are one of those parts you don't think about until cooling problems show up. I've seen motors overheat just because this tube was bent, clogged, or not seated right after service. It's what carries water from the pump up into the powerhead, so it has to be clean and properly aligned. When it's right, you get steady cooling and no surprises out on the water.. Key Features. • Direct Water Flow Channel - Transfers cooling water from the pump to the engine.• Consistent Cooling Support - Helps maintain stable engine temperatures during operation.• Durable Metal Construction - Built to handle heat, vibration, and continuous water flow.• Corrosion-Resistant Design - Performs reliably in both freshwater and saltwater environments.• Exact Yamaha Fitment - Matches factory specifications for proper alignment and sealing.. Engine & Boat Compatibility. Designed for Yamaha outboard engines utilizing internal wat