Yamaha - Water Tube Cooling System Component 6J8-44361-10-00. Overview. Cooling issues on an outboard can sneak up fast, and a lot of times it comes down to something simple like water flow not moving the way it should. This tube is what carries that flow up through the motor, so if it's off, everything downstream feels it. I've seen engines run hot just from a misaligned or worn tube during reassembly. When it's right, you don't think about it-and that's exactly how it should be.. Key Features. Consistent Water Delivery - Moves cooling water from the lower unit to the powerhead without restriction.. Precision Fit Alignment - Ensures proper seating between pump and engine for reliable flow.. Durable Construction - Built to handle vibration, heat, and constant water exposure.. Corrosion-Resistant Design - Holds up in both freshwater and saltwater environments.. Supports Cooling Efficiency - Helps maintain stable engine temperatures under load.. Compatibility. Designed for Yamaha outboar