Yamaha - Impeller Housing Jet Pump Component 6CR-R1312-00-00. Overview. If you've spent time around Yamaha jet pumps, you know how much the housing affects the way the boat or WaveRunner actually feels on the water. I've seen worn housings cause cavitation and kill acceleration even when everything else looked fine. The Yamaha Impeller Housing 6CR-R1312-00-00 is what keeps water moving clean and controlled through the pump. When it's in good shape, you get that strong hookup and smooth pull Yama