91351-ZY1-871 O-Ring (2.4X12.3) - Overview. The 91351-ZY1-871 O-Ring (2.4X12.3) is an essential sealing component in Honda marine engine systems. This O-Ring plays a critical role in maintaining the integrity of various engine subsystems by providing reliable sealing to prevent fluid or gas leaks. Designed to fit precisely within the system, it supports optimal performance and ensures longevity by preventing contamination and wear.. Key Features. Exact OEM specification O-Ring with dimensions 2.