90512-ZVA-000 Washer Plain (6mm) - Overview. The 90512-ZVA-000 Washer Plain (6mm) is an essential hardware component used in Honda marine engine systems. It supports the rigging and mechanical fastening systems by evenly distributing load and protecting mating surfaces from damage during fastening. By maintaining factory specifications and dimensions, this washer ensures reliability and a secure fit, crucial for sustaining optimal marine engine performance and durability.. Key Features. Genuine