Mercury Thermostat Assembly, 140°F, Select 135-400hp Verado 8M0174561

Mercury Thermostat Assembly 8M0174561 is an OEM replacement 140°F thermostat and housing assembly for select Mercury Verado outboards from 135-400 HP.

Compatible with select Mercury Verado applications including:

• 135-200 HP 4-cylinder Verado
• 200-300 HP 6-cylinder Verado
• 200-300 HP 6-cylinder Gen V Verado
• 350-400 HP 6-cylinder Verado

The assembly features a corrosion-resistant, high-temperature molded composite housing designed for durability in marine cooling systems. The housing incorporates a 90-degree bend on the outlet side and includes the internal stainless steel 140°F thermostat.

This is the complete thermostat housing and thermostat assembly. Additional seals, gaskets, clamps, and attaching hardware are sold separately. Mercury recommends replacing the applicable housing seals, gaskets, and clamps during installation to help ensure proper cooling system operation.

Because this assembly is used across several generations of Verado engines, compatibility should be confirmed using the engine serial number before ordering.

Supersedes/Replaces: 892864T04

To Confirm Compatibility: Contact our team with your engine serial number at (727) 596-5929 before ordering.