Yamaha - Water Tube Cooling System Component 6L2-44361-10-00. Overview. The water tube is one of those parts that quietly does its job-until it doesn't. It carries cooling water from the pump up to the powerhead, so any issue here can throw off the whole system. I've seen motors overheat just because the tube was slightly bent or not sealing correctly after install. Keeping this piece in good condition makes sure your engine stays cool and runs the way it should.. Key Features. Efficient Water Transfer - Moves cooling water from the lower unit to the engine block.. Precision Alignment Fit - Ensures proper connection between pump and powerhead.. Durable Construction - Built to handle vibration, heat, and continuous water flow.. Factory-Spec Fitment - Matches Yamaha cooling systems for proper sealing and performance.. Supports Engine Cooling - Helps maintain consistent operating temperature under load.. Engine & Boat Compatibility. Designed for Yamaha outboard engines with compatible coo