63731-ZZ3-000ZB R Nhb14M Cover - Overview. The 63731-ZZ3-000ZB R Nhb14M Cover is a crucial right lower mounting cover designed specifically for Honda marine engine systems. It serves as a protective housing component, helping to maintain the structural integrity and efficient operation of the engine by shielding internal parts from environmental damage and wear. This cover ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Genuine OEM