40105-ZY3-C01 Case Grommet A - Overview. The 40105-ZY3-C01 Case Grommet A is an essential component within Honda marine engine systems. It functions as a rubber seal designed specifically for the engine case, helping to prevent the ingress of water, debris, and contaminants into critical engine parts. By maintaining a secure and waterproof seal, the grommet ensures the reliable operation and longevity of the engine system. Engineered to seamlessly integrate with existing parts, this grommet pres