Yamaha - Water Tube Cooling System Tube 6CJ-44361-00-00. Overview. Cooling flow is something you don't want to guess about on a Yamaha, and this water tube is a key part of making sure everything stays in check. It moves water from the lower unit up into the engine, and if it's off, the motor can heat up fast. I've seen simple issues like a worn or misaligned tube cause bigger problems than expected. When it's set up right, water flow stays steady and the engine runs cool and consistent.. Key Features. • Direct Water Flow Path - Transfers cooling water efficiently from the lower unit to the engine.• Precision Fit Design - Ensures proper alignment for consistent and uninterrupted water flow.• Durable Tube Construction - Built to handle internal pressure, heat, and continuous operation.• Reliable Cooling Support - Helps maintain proper engine temperature during extended use.• Corrosion-Resistant Build - Designed to withstand freshwater and saltwater environments.. Engine & Boat Compatibi