90166-ZW4-000 Flange (6x28) Bolt - Overview. The 90166-ZW4-000 Flange (6x28) Bolt is a critical fastener designed specifically for Honda marine engine systems. This bolt plays an essential role in securely fastening components within the engine assembly, keeping the system stable and operational under marine conditions. Carefully engineered to match factory specifications, this bolt ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. G