31639-ZY3-003 Rr End Cover - Overview. The 31639-ZY3-003 Rr End Cover is an essential component designed specifically for Honda marine engine systems. This rear end cover provides critical protection and enclosure for internal parts at the rear section of the marine engine. By shielding key internal mechanisms from environmental factors like water and debris, it ensures smooth operation and extends the life of your equipment. Precisely manufactured to match factory dimensions, it ensures seamles