Yamaha - Water Tube 1 6FM-44361-00-00. Overview. The Yamaha Water Tube 1 6FM-44361-00-00 is one of those parts that keeps your engine cool without drawing any attention-until something's off. When this tube gets clogged or worn, you'll usually see it in weak water flow or rising temps, especially at idle. It directs cooling water through the powerhead, so everything depends on it staying clear and properly seated. If you're chasing an overheating issue or doing cooling system maintenance, this is a smart part to replace.. Key Features. • Efficient Water Flow Routing - Directs cooling water through the engine to maintain proper temperature.. • OEM Fit Precision - Built to Yamaha specifications for proper alignment and secure installation.. • Corrosion-Resistant Design - Handles constant exposure to water and harsh marine conditions.. • Engine Protection Support - Helps prevent overheating and protects internal engine components.. Compatibility. Compatible with select Yamaha outboard eng