Yamaha - Water Tube Cooling System Transfer 6H3-44361-11-00. Overview. The water tube is one of those parts that has to be right every time you drop the lower unit back on. I've seen good water pumps fail to deliver proper flow just because the tube didn't seat correctly or was slightly damaged. It's a simple piece, but it carries all the cooling water up to the powerhead. When it's lined up and sealed right, your cooling system does exactly what it's supposed to.. Key Features. Direct Cooling Water Transfer - Moves water from the lower unit to the engine for proper temperature control.. Precision Alignment Fit - Built to Yamaha specs to ensure correct positioning during installation.. Corrosion-Resistant Material - Designed to withstand constant exposure to water and marine conditions.. Consistent Cooling Support - Helps maintain steady water flow to prevent overheating.. Service-Friendly Component - Ideal to inspect or replace during lower unit or water pump service.. Engine & Boat C