90023-ZY6-000 Special (6X31) Bolt - Overview. The 90023-ZY6-000 Special (6X31) Bolt is a critical component within Honda marine engine systems. This specialized bolt supports various mechanical structural functions essential for maintaining the integrity and reliability of Honda marine equipment. Precisely engineered, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Specialized bolt designed to exact specifications, measuring 6x3