Yamaha - Water Tube Assembly Cooling System Water Transfer 6EE-G4360-00-00. Overview. Water tubes are one of those parts you don't notice until the engine starts running hotter than it should. I've worked on plenty of small Yamaha outboards where a misaligned or corroded tube caused cooling issues that didn't show up right away. This piece is what carries water from the pump up into the powerhead, so it has to be lined up and sealed correctly. When it's right, the cooling system just works witho