91301-ZW4-003 O-Ring (6.9X1.45) - Overview. The 91301-ZW4-003 O-Ring (6.9X1.45) is a critical sealing component used in Honda marine engine systems. It serves primarily within the gear case and extension case assemblies, playing an essential role in preventing oil and fluid leaks while ensuring the marine engine operates reliably and efficiently. This O-Ring is designed to maintain tight seals under varying pressures and marine environmental conditions, ensuring seamless integration with existin