90101-HW1-671 Flange (8X25) Bolt - Overview. The 90101-HW1-671 Flange (8X25) Bolt is an essential component for Honda marine engine systems. This flange bolt, measuring 8mm in diameter and 25mm in length, plays a crucial role in securely fastening parts within the marine engine assembly to ensure reliable performance and durability. Engineered to original equipment manufacturer standards, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Fe