16861-ZY1-900 Fuel Tube B - Overview. The 16861-ZY1-900 Fuel Tube B is an essential fuel line component designed specifically for Honda marine engine systems. This tube supports the fuel system by efficiently transporting fuel from the tank toward the engine's fuel supply mechanism, ensuring consistent engine operation and reliability. As a critical part of the fuel delivery system, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features