16966-MR5-000 Fuel Tube Joint - Overview. The 16966-MR5-000 Fuel Tube Joint is an essential component of Honda marine engine fuel systems. Designed specifically to connect fuel tubes securely, it ensures proper fuel delivery and prevents leaks, which is critical for reliable engine operation. This joint integrates smoothly with existing fuel system parts, preserving optimal performance and durability.. Key Features. Connects fuel tubes within the fuel system to maintain a secure and leak-proof c