23172-ZW5-003 Mount Case Gasket - Overview. The 23172-ZW5-003 Mount Case Gasket is an essential sealing component designed to prevent leaks and maintain the integrity of Honda marine engine systems. It supports the mounting case system by ensuring a secure and reliable seal, which keeps lubricants and fluids contained, preventing contamination and potential damage. Precision engineered for seamless integration with existing parts, this gasket maintains optimal performance and durability under ma