91503-ZY3-000 Unit Collar - Overview. The 91503-ZY3-000 Unit Collar is a crucial component in Honda marine engine systems. This OEM genuine part acts as a collar to secure or connect other components within the marine unit, ensuring reliable operation and structural support. Designed to match factory specifications, it guarantees seamless integration with existing hardware, maintaining optimal performance and durability.. Key Features. Genuine OEM part specifically designed for Honda marine equi