Yamaha - Water Pump Cover Cooling System Component YF1-43847-37-70. Overview. When you're servicing a Yamaha water pump, the cover is one of those parts that has to seal perfectly or you'll run into cooling issues fast. I've seen pumps lose pressure just from a worn or slightly warped cover. The Yamaha Water Pump Cover YF1-43847-37-70 helps keep everything sealed and aligned so the pump can do its job properly. It's a simple part, but it's critical for keeping water moving through the system the right way.. Key Features. • Seals Water Pump Assembly - Maintains proper pressure and flow within the cooling system.. • Yamaha Engineered Fit - Built to factory specifications for precise alignment and sealing.. • Durable Construction - Designed to withstand constant water exposure, heat, and engine vibration.. • Supports Cooling Efficiency - Helps ensure consistent water circulation through the engine.. • Direct Replacement Component - Installs in place of the original cover during pump servi