Yamaha - Impeller - YJA-01212-27-01Yamaha Water Pump Impeller YJA 01212 27 01 Overview The Yamaha YJA 01212 27 01 Water Pump Impeller is a genuine original equipment manufacturer component designed to circulate cooling water through the engine and maintain proper operating temperature. The impeller is a critical part of the water pump system, using flexible blades to draw water from the lower unit and push it through the engines cooling passages. A properly functioning impeller ensures