Yamaha - Water Pump Housing Cooling System Component 61A-44311-01-00. Overview. The Yamaha Water Pump Housing 61A-44311-01-00 is one of those parts that quietly keeps your cooling system working the way it should. When it starts to wear, warp, or score inside, you'll notice it in reduced water pressure or inconsistent cooling. It's what surrounds and supports the impeller, so it needs to stay clean and in good shape. If you're rebuilding a water pump, this is one of those parts you don't skip..