90018-Zvt-000 Bolt-Washer (12X70) - Overview. The 90018-Zvt-000 Bolt-Washer (12X70) is an essential fastener component used in Honda marine engine systems. This bolt washer, measuring 12mm by 70mm, plays a crucial role in securing various parts within the engine's mechanical assemblies, ensuring structural integrity and reliability during operation. Designed specifically for Honda marine systems, this bolt-washer ensures seamless integration with existing parts, maintaining optimal performance a