13344-ZX2-003 Bearing D Main (Lower) - Overview. The 13344-ZX2-003 Bearing D Main (Lower) is an essential component of Honda marine engine systems. This main bearing supports the lower end of the engine's crankshaft, playing a crucial role in maintaining the smooth mechanical motion necessary for reliable engine operation. Engineered to fit perfectly within the lower bearing system, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features