90108-ZY1-870 Bolt Hex (8X203) - Overview. The 90108-ZY1-870 Bolt Hex (8X203) is a precision-engineered fastener designed specifically for Honda marine engine systems. It plays a vital role in securely fastening components within the engine assembly, ensuring reliability and optimal operation under marine conditions. Crafted to fit seamlessly with Honda's active marine engines, this bolt upholds stringent factory specifications, providing secure mounting and mechanical stability essential for pe