91310-PC6-004 O-Ring (15.5X2.7) - Overview. The 91310-PC6-004 O-Ring (15.5X2.7) is a crucial sealing component in Honda marine engine systems. It is designed specifically for use within the oil pump and water passage sealing systems, helping to maintain a leak-proof environment critical for engine reliability and efficiency. Manufactured to the highest OEM standards, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Precision-engi