90161-ZW9-830 Flange (10X20) Bolt - Overview. The 90161-ZW9-830 Flange (10X20) Bolt is a critical component in Honda marine engine systems. It functions as a secure fastening element designed to maintain structural integrity in areas requiring precise flange attachment. This bolt plays a vital role in keeping your marine equipment operating reliably by securing flange joints and ensuring efficient mechanical stability. Engineered to factory specifications, it ensures seamless integration with ex