90502-ZV4-000 Plain (5mm) Washer - Overview. The 90502-ZV4-000 Plain (5mm) Washer is an essential OEM component used in Honda marine engine systems. This plain washer plays a critical role in fastening and distributing load evenly to maintain the integrity and reliable operation of your marine equipment. Its precise 5mm inner diameter fitting makes it suitable for use in various Honda marine hardware applications, ensuring seamless integration with existing parts and maintaining optimal performa