90601-ZE2-000 Drain (12mm) Washer - Overview. The 90601-ZE2-000 Drain (12mm) Washer is an essential sealing component in Honda marine engine systems. Designed to fit around the 12mm drain plug, this washer ensures a tight, leak-free seal critical for maintaining engine integrity and preventing fluid loss during operation and maintenance. Manufactured from durable alloy steel with a stainless steel exterior finish, it offers robustness and resistance to corrosion in marine environments, ensuring