90550-ZV5-821 Washer Spring (5Mm) - Overview. The 90550-ZV5-821 Washer Spring (5Mm) is a critical component in Honda marine engine systems. This 5mm spring washer serves as a fastener element that ensures secure and reliable connections by providing spring tension and maintaining proper spacing between connected parts. It supports structural integrity within various mechanical assemblies, making it essential for optimal engine performance and durability. Crafted to meet the original factory spec