90029-Zz5-M00 Bolt-Washer (5X18) - Overview. The 90029-Zz5-M00 Bolt-Washer (5X18) is a critical fastening component used in Honda marine engine systems. This bolt-washer part plays an essential role in securely mounting engine components and accessories, ensuring reliable operation and structural integrity during marine conditions. Designed specifically for Honda engines, it provides seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Precisel