Yamaha - Water pump assy - YF1-43847-30-30Yamaha Water Pump Assembly Engine Cooling System YF1 43847 30 30 Overview If theres one part you dont want failing on the water, its the water pump. Ive seen Yamaha engines go from running perfectly to overheating fast when the pump stops doing its job. The Yamaha Water Pump Assembly YF1 43847 30 30 keeps coolant moving through the engine so temperatures stay where they should. Its one of those components you trust every time you start the motor,