Yamaha - Water Pump Repair Kit Cooling System 6E0-W0078-A5-00. Overview. When it comes to keeping a Yamaha running cool, I always tell people not to cut corners on the water pump. By the time you're opening it up, it usually makes sense to replace everything instead of guessing which part might fail next. I've seen guys swap just an impeller and end up right back in the shop a few trips later. A full repair kit like this gets the job done right the first time and keeps water flow strong.. Key Features. Complete Service Kit - Includes essential components needed for a full water pump rebuild.. Restores Cooling Performance - Helps bring water pressure and flow back to proper levels.. Durable Marine-Grade Materials - Built to handle heat, friction, and debris in real-world conditions.. OEM Matched Components - Designed to work together for proper fit and reliable operation.. Engine & Boat Compatibility. Designed for Yamaha 2-stroke outboard engines using standard water pump systems. Commo