91251-ZV0-003 Seal (11X21X8) - Overview. The 91251-ZV0-003 Seal (11X21X8) is a crucial component within Honda marine engine systems, specifically designed as a water seal to prevent fluid leakage and contamination ingress in the gear case propeller system. This seal supports the vertical shaft propeller system of Honda's outboard engines, ensuring the internal components remain protected from water intrusion and wear, which is vital for maintaining engine reliability and longevity.. Key Features