90509-ZV4-000 Shift Washer - Overview. The 90509-ZV4-000 Shift Washer is a small yet vital metal component within Honda marine engine systems, specifically supporting the shifting mechanism. This OEM shift washer ensures precise gear engagement, contributing to the smooth and reliable operation of Honda outboard engines. Designed to exact factory specifications, it fits seamlessly with other rigging components, maintaining optimal performance and durability.. Key Features. Genuine OEM part engin