17621-ZV0-030 Fuel Cap Body - Overview. The 17621-ZV0-030 Fuel Cap Body is an essential component of Honda marine engine systems. It forms the physical structure of the fuel cap, providing a durable and reliable seal to prevent fuel leaks and ensure proper tank ventilation. This part is critical for maintaining fuel system integrity and supporting the overall performance of your Honda marine engine. Engineered to match factory specifications, it ensures seamless integration with existing parts,