Protect your marine investment with MERCURY factory part F40278. factory-spec sealing that holds up season after season — exactly what your engine was designed around.

Quality matters when you’re on the water. Leaks mean downtime and expensive repairs. MERCURY factory seals aren’t just better — they’re engineered specifically for marine duty with sealing integrity. Precision manufacturing, proven materials, exact specifications. Not aftermarket guesswork, but OEM reliability you can trust.

MERCURY part F40278 delivers no more leaks — just reliable performance — exactly what your engine needs. Factory engineering means reliable starts, smooth operation, and fewer surprises on the water. That’s been our experience after four decades in marine parts.

FITS: MERCURY marine engines and outboards. Verify part number F40278 with your engine’s parts diagram to ensure exact compatibility.

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STAY OUT ON THE WATER LONGER WITH GENUINE OEM PARTS FROM US BOATWORKS.

Over 2 million parts in stock including NLA and hard-to-find parts.

Can’t find what you’re looking for? Call or text us: 913-342-0011