23172-ZVT-B13 Mount Case Gasket - Overview. The 23172-ZVT-B13 Mount Case Gasket is a vital sealing component within Honda marine engine systems. It serves to create a watertight seal for the engine's mounting case, preventing water ingress and ensuring the engine remains fully operational and protected from external moisture. Designed with precision to Honda's factory specifications, this gasket ensures seamless integration with existing parts, maintaining optimal performance and durability.. Ke