90451-ZV4-000 Lock (27mm) Washer - Overview. The 90451-ZV4-000 Lock (27mm) Washer is an essential component in Honda marine engine systems, designed to secure fasteners and prevent loosening due to vibration and movement during operation. This washer supports the mechanical fastening system and plays a critical role in maintaining the integrity and reliability of connections within the engine assembly. By ensuring fasteners remain tight, it contributes significantly to the overall durability and