Yamaha - Water Pump Repair Kit - 6E0-W0078-A2-00 - Engine Models 4 & 5Yamaha Water Pump Repair Kit Cooling System 6E0 W0078 A2 00 Overview When youre servicing the water pump on these smaller Yamahas, its usually best to just do it all at once. Ive seen too many cases where only the impeller gets replaced, and the rest of the worn parts end up causing issues not long after. A full kit like this takes care of everything in one go and saves you from opening it back up again. Once its done right, you get solid water flow