Yamaha Impeller 705-12457-00-00. Overview. The Yamaha Impeller 705-12457-00-00 is a genuine original equipment manufacturer component designed to keep your engine's cooling system functioning efficiently. As the core of the water pump, this impeller circulates water through the engine, helping regulate temperature and prevent overheating during operation.. Built to Yamaha's exact specifications, this impeller ensures a precise fit and dependable performance. It is a critical maintenance componen