Yamaha - Impeller Housing Water Pump Component 6R7-51312-03-00. Overview. When you're servicing a Yamaha water pump, it's easy to focus on the impeller and overlook the housing-but that's where a lot of problems start. I've seen fresh impellers installed into worn housings, and the cooling performance still wasn't right. The Yamaha Impeller Housing 6R7-51312-03-00 gives the impeller the proper surface and clearance to move water efficiently. If the housing is worn, the whole cooling system suffe