The Yanmar 124223-42140 is a genuine OEM gasket used in Yanmar marine engines, primarily within the seawater pump or cooling system assembly. Often referred to as the “Gasket Outer Plate,” it serves as a sealing component between mating surfaces to prevent coolant or seawater leaks. This gasket is commonly found in Yanmar QM-series engines, such as the 2QM and 3QM models. Built to Yanmar’s high manufacturing standards, it ensures a proper seal and reliable performance in marine cooling applications.