90301-ZY9-000 Hex (12mm) Nut - Overview. The 90301-ZY9-000 Hex (12mm) Nut is an essential hardware component for Honda marine engine systems. This genuine OEM nut plays a critical role in fastening and securing various parts of the marine engine rigging and accessory systems, ensuring reliable operation and durability. Designed to meet Honda's factory specifications, it guarantees seamless integration with existing components, maintaining optimal performance and longevity.. Key Features. High-qu