63731-ZY3-A03ZB R *NHB14M* Cover - Overview. The 63731-ZY3-A03ZB R *NHB14M* Cover is a crucial component in Honda marine engine systems specifically designed for the right mounting lower section. Its primary role is to protect and seal vital engine parts, ensuring reliable performance and longevity. This cover is painted in Aqua Marine Silver Metallic (NHB14M) color, which not only enhances visual appeal but also meets factory specifications for finish and durability. Engineered for seamless int