17624-ZZ5-003 Fuel Cap Gasket - Overview. The 17624-ZZ5-003 Fuel Cap Gasket is an essential rubber sealing component within the fuel system of Honda marine engine systems. Its primary role is to provide a secure and reliable seal on the fuel cap, preventing fuel vapor leaks and protecting the fuel tank from contamination by external elements. Designed to fit perfectly within the fuel cap assembly, it ensures seamless integration with existing parts, maintaining optimal performance and durability