91309-PJ7-010 O-Ring (11.5X3.5) - Overview. The 91309-PJ7-010 O-Ring (11.5X3.5) is a critical sealing component used in Honda marine engine systems. This O-ring supports the fuel and oil sealing systems, preventing fluid leaks to maintain engine efficiency and reliability. Engineered to meet factory specifications with precise dimensions of 11.5 mm outer diameter and 3.5 mm thickness, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Featur