Yamaha - Water Pump Repair Kit Cooling System Service Kit 6H3-W0078-01-00. Overview. The Yamaha Water Pump Repair Kit 6H3-W0078-01-00 is one of those kits you keep on hand if you want to stay ahead of cooling issues. When the pump starts wearing out, you'll notice weak water flow or rising temps, especially at idle. This kit gives you everything you need to refresh the water pump in one go instead of piecing it together. If you're doing routine maintenance or rebuilding the cooling system, this is the kind of job that saves headaches later.. Key Features. • Complete Pump Service Kit - Includes key components needed to rebuild and restore water pump performance.. • OEM Fit Precision - Designed to match Yamaha specifications for proper fit and reliable operation.. • Restores Cooling Efficiency - Helps bring back strong water flow and proper engine temperature control.. • Durable Marine Components - Built to handle heat, friction, and harsh marine environments.. Engine & Boat Compatibilit