91251-ZV5-003 Seal (17X30X7) - Overview. The 91251-ZV5-003 Seal (17X30X7) is a genuine OEM oil seal designed for Honda marine engine systems. This seal prevents water intrusion and fluid leaks within the lower unit gearcase, helping to maintain the integrity and reliable operation of your marine engine. It ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Precisely sized 17 mm inner diameter, 30 mm outer diameter, and 7 mm thickness