56511-ZW4-H11 Tube (Outer) - Overview. The 56511-ZW4-H11 Tube (Outer) is a critical component in Honda marine engine systems, primarily supporting the rigging and accessory system. This outer tube serves as a protective conduit for wiring harnesses and other rigging elements, ensuring these delicate parts are shielded from environmental factors such as water, salt, and mechanical wear, thus maintaining engine reliability and durability. Engineered to match exact factory specifications, this OEM