90501-ZW5-000 Shift Shaft Washer - Overview. The 90501-ZW5-000 Shift Shaft Washer is an essential part in the Honda marine engine systems, designed to function within the shift shaft assembly. This washer maintains proper spacing and reduces friction or wear between moving components, ensuring the shifting mechanism operates smoothly and reliably. As an OEM component, it guarantees a precision fit with factory-matched dimensions, tolerances, and materials.. Key Features. Shift shaft washer desig