91303-377-000 O-Ring (13.8X2.5) - Overview. The 91303-377-000 O-Ring (13.8X2.5) is a precisely engineered sealing component used within Honda marine engine systems. This O-ring plays a critical role in preventing leaks and maintaining pressure integrity within the system it supports. Designed specifically to match Honda's factory specifications, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. High-quality O-ring with an inner di