63718-ZVL-000 Mount Case Seal - Overview. The 63718-ZVL-000 Mount Case Seal is an essential OEM sealing component specifically designed for Honda marine engine systems. It plays a critical role in preventing leaks and protecting the mount case from exposure to water, dirt, and other environmental contaminants, ensuring the engine operates reliably and efficiently.. Key Features. Genuine Honda OEM part designed to exact factory specifications, tolerances, and dimensions.. Provides effective seali