Yamaha - Water Pump Repair Kit Cooling System Service Kit 6CJ-W0078-01-00. Overview. Anyone who maintains Yamaha outboards knows the water pump is one of those parts you stay ahead of, not behind. The Yamaha Water Pump Repair Kit 6CJ-W0078-01-00 gives you everything needed to refresh the pump in one service, restoring proper water flow through the engine. When impellers and wear plates start to age, cooling performance drops and temperatures can climb when you least expect it. A complete pump se