13321-PZ1-003 Main Bearing A - Overview. The 13321-PZ1-003 Main Bearing A is a critical component in Honda marine engine systems. It plays a vital role in supporting the crankshaft, ensuring smooth and reliable engine operation. Designed to fit perfectly within the engine's internal system, it guarantees seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. This main bearing supports the crankshaft, allowing it to rotate smoothly within the engi