Don’t miss another weekend. This genuine Mercury Marine SEAL, CYLINDER ships fast and installs easily – get back on the water where you belong.

Factory-built to exact Mercury Marine specifications, this seal ensures reliable operation across all engine RPM ranges. Part number F40278 is manufactured to exact Mercury Marine factory specifications for precision installation and optimal performance. Constructed from premium marine-grade materials designed to withstand harsh saltwater and freshwater environments.

Cut-rate alternatives might look similar, but they’re not engineered to Mercury’s exacting standards. Part F40278 delivers consistent performance because it’s built right — the same way Mercury does it at the factory.

Compatible Mercury Marine Engines

FITS: 100-115HP CHRYSLER

• Fits CHRYSLER 100-115HP engines
• Compatible HP: 100HP, 105HP, 115HP
• Covers 24 serial number ranges
• Configurations: Outboard
• OEM genuine Mercury Marine part

COMPLETE SERIAL NUMBER COMPATIBILITY:

100HP Models

• 100HP OUTBOARD (Chrysler)

105HP Models

• 105HP OUTBOARD (Chrysler)

115HP Models

• 115HP OUTBOARD (Chrysler)

Not sure where to find your engine’s serial number? View our quick reference guide to locate it on your Mercury Marine engine.

Verification & Support

Want to verify compatibility for part F40278? Use our parts finder tool for instant confirmation. Still have questions? No problem – use the contact buttons at the bottom of this page to reach us by text, call, or email

Serving boaters for over 40 years. Competitive pricing, same-day shipping on most orders.