91310-PH3-003 O-RING (18X2.4) - Overview. The 91310-PH3-003 O-RING (18X2.4) is a vital component in Honda marine engine systems. Serving as a precise sealing ring, it prevents fluid and gas leaks by establishing a secure, tight barrier between mating parts. Designed for the marine application, this O-ring ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. OEM Genuine Honda component precisely matching factory specifications with dimen