Yamaha - Water Pump Repair Kit Cooling System Service Kit 6N0-W0078-A0-00. Overview. The Yamaha Water Pump Repair Kit 6N0-W0078-A0-00 is one of those maintenance kits you don't skip if you want your small outboard running cool and reliable. On 6 and 8 horsepower motors, even a slight drop in water flow shows up fast, especially at idle. This kit gives you the core components to rebuild the pump instead of chasing individual parts. If you're doing routine service or fixing cooling issues, it's a solid, complete solution.. Key Features. • Complete Pump Rebuild Kit - Includes essential components needed to restore full water pump performance.. • OEM Fit Precision - Built to Yamaha specifications for proper alignment and dependable operation.. • Restores Cooling Efficiency - Helps bring back strong water flow and stable engine temperatures.. • Compact Marine Design - Designed specifically for small outboards with consistent performance in tight housings.. Engine & Boat Compatibility. • 6 1