Thermostat 120° Degree Mercury Mariner Sears Outboard (6 - 125 HP) 18-3549 14586

Thermostat 120° for Mercury Mariner Sears Outboard

This 120° thermostat for Mercury, Mariner, and Sears outboards replaces OEM cross-reference numbers 18-3549 and 14586, regulating engine temperature for 6 to 125 HP applications.

Overview

This Thermostat 120° is designed for Mercury, Mariner, and Sears outboard engines within the 6 to 125 HP range. Replacing OEM part numbers 18-3549 and 14586, this Thermostat 120° opens at the specified temperature to maintain consistent cooling. It suits marine mechanics and DIY boat owners needing a direct thermostat replacement.

Built For Performance

• 120° opening temperature for reliable engine warm-up
• Replaces OEM part numbers 18-3549 and 14586
• Fits outboard motors from 6 to 125 HP
• Compatible with Mercury, Mariner, and Sears outboards

Fits These Machines

• for Mercury outboard engines 6 to 125 HP
• for Mariner outboard engines 6 to 125 HP
• for Sears outboard engines 6 to 125 HP

On-The-Job Use

• Replacing a stuck-open or stuck-closed outboard thermostat
• Maintaining proper engine operating temperature in salt or freshwater
• Restoring consistent cooling in Mercury, Mariner, and Sears outboards
• Serving as a tune-up component during cooling system service

Specs At A Glance

Good To Know

Q: What temperature does this thermostat open at? A: This thermostat opens at 120° to help the outboard reach normal operating temperature.

Q: Does this fit all Mercury outboards? A: This thermostat is intended for Mercury, Mariner, and Sears outboard models within the 6 to 125 HP range, so verify your specific serial number before ordering.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.