17515-ZVD-000 Tank Cap Rubber - Overview. The 17515-ZVD-000 Tank Cap Rubber is a vital component of Honda marine engine fuel systems. It functions as the rubber seal for the fuel tank cap, ensuring a tight and reliable closure that prevents fuel leaks and contamination. This small but essential accessory plays a critical role in maintaining the integrity and safety of your marine engine's fuel system, helping your boat operate smoothly and efficiently. Made from durable rubber, the cap is design