90517-921-000 Joint Tube Washer - Overview. The 90517-921-000 Joint Tube Washer is a critical component in Honda marine engine systems, designed to provide an effective seal for joint tubes within the fuel or rigging assemblies. This washer supports proper sealing to prevent leaks and maintain the integrity of connected systems. Specifically engineered for Honda marine applications, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features