Yamaha - Water Pump Repair Kit Cooling System Service Kit 6J8-W0078-A1-00. Overview. The Yamaha Water Pump Repair Kit 6J8-W0078-A1-00 is one of those kits you grab when you want to take care of the whole cooling system in one shot. On older 2-stroke motors, worn pump components can sneak up on you with weak water flow or rising temps. This kit gives you the key pieces to refresh the pump instead of chasing individual parts. If you're doing maintenance or bringing an older motor back to life, this is a solid place to start.. Key Features. • Complete Pump Service Kit - Includes essential components needed to rebuild and restore water pump performance.. • OEM Fit Precision - Designed to Yamaha specifications for proper fit and reliable operation.. • Restores Cooling Efficiency - Helps bring back strong water flow and proper temperature control.. • Durable Marine Components - Built to handle heat, friction, and long-term use in marine environments.. Engine & Boat Compatibility. • 30 1995 a