Don’t gamble with your Mercury’s reliability. This genuine SEAL-Thermostat COMPONENT OF POWERHEAD ASSEMBLY [800-818153A37] OR [800-818153A53] ensures long-term performance and protects your investment in quality marine power.

Manufactured to strict Mercury Marine quality standards, this seal ensures reliable operation across all engine RPM ranges. Part number F664914 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.

Smart boat owners know: buying cheap parts twice costs more than buying genuine Mercury once. Part F664914 delivers long-term value through superior materials and precision manufacturing.

Compatible Mercury Marine Engines

FITS: 120-125HP FORCE, SPORTJET

• Fits FORCE, SPORTJET 120-125HP engines
• Compatible HP: 120HP, 125HP
• Covers 24 serial number ranges
• Configurations: Jet Drive, Outboard
• OEM genuine Mercury Marine part

COMPLETE SERIAL NUMBER COMPATIBILITY:

120HP Models

• 120HP JET (Sportjet): 0E080400-0E145579, 0E095088-0E141088, 0E145580-0E151579, 0E151580-0E288445, 0E288446-0E344999, 0E141089-0E202999, 0E203000-0E315904, 0E315905-0E341982
• 120HP OUTBOARD (Force): 0E000001-0E093699, 0E138600-0E202999, 0E203000-0E287999, 0E288000-0E344999, 0E345000-0E369299, 0E093700-0E138599

125HP Models

• 125HP OUTBOARD (Force)

Don’t know where your serial number is? Our quick reference guide shows exactly where to find it on Mercury Marine engines.

Verification & Support

Verify part F664914 works with your Mercury using our parts finder tool. Have questions? Reach out using the contact buttons at the bottom of this page — our team is here to help by text, call, or email

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