94101-04200 Plain (4mm) Washer - Overview. The 94101-04200 Plain (4MM) Washer is an essential component in Honda marine engine systems. This flat, ring-shaped washer supports the rigging and accessory systems by evenly distributing the load of fasteners to prevent damage and loosening. It plays a vital role in maintaining reliable connections and preventing mechanical issues in the marine environment. Designed precisely to match factory specifications, the washer ensures seamless integration wit