Yamaha - Water Pump Repair Kit Cooling System Service 6H3-W0078-1A-00. Overview. If you run your motor regularly, the water pump is one of those things you stay ahead of, not react to. I've seen too many overheating issues that could've been avoided with a simple rebuild like this. When the pump starts losing efficiency, it doesn't take long for temps to climb. This kit gives you everything you need to bring the cooling system back to where it should be.. Key Features. Complete Pump Service Kit - Includes the essential components needed to restore water pump performance.. Reliable Cooling Flow - Helps maintain steady water circulation to protect against overheating.. OEM Fitment Components - Built to Yamaha specifications for proper alignment and sealing.. Durable Internal Parts - Designed to handle continuous operation in harsh marine environments.. Preventative Maintenance Solution - Ideal for routine service intervals to avoid unexpected failures.. Engine & Boat Compatibility. Desig