12231-ZVL-000 R Cover - Overview. The 12231-ZVL-000 R Cover is a crucial component for Honda marine engine systems. This camshaft thrust cover supports the cylinder head system by protecting critical mechanical parts and ensuring reliable operational integrity. Designed to fit perfectly within the engine assembly, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Specifically designed as the Right Camshaft Thrust Cover for Honda m