Mercury – Thermostat | Cooling System | Factory Marine Finish | 991551 Yamaha F150 Outboard Covers This product has been superseded

This product has been superseded by: M879243

Fits all V-4 and V-6 engines to a maximum of 150 hp

Fits Frames up to 3"W x 4-1/4"H

59708P VoltmeterWARNING: This product can expose you to chemicals which are known to the State of California to cause cancer

Mercury – Thermostat | Cooling System | Factory Marine Finish | 991551 Yamaha F150 Outboard Covers This product has been supersededMercury Thermostat Cooling System Factory Marine Finish 991551 Overview Theres a certain comfort in watching your engine settle into that perfect operating temperaturesteady, calm, and exactly where it should be. Its the feeling you get when youve been on the water long enough to know when something is right, and when something isnt. A good thermostat doesnt shout for attention; it simply keeps the heart of your boat running smooth and predictable.