Description
Mercury 8M0228544 Upper Thermostat Assembly 350-400HP 5.7L V10 FourStroke
The Mercury 8M0228544 upper thermostat assembly is designed for select 350-400HP 5.7L V10 FourStroke outboards. This thermostat helps regulate engine cooling temperature for proper performance and efficiency on supported V10 applications. Published fitment references identify this part as an upper thermostat assembly for 5.7L V10 Verado applications and note that it is sold individually.
Applications
Fits select Mercury 5.7L V10 350-400HP FourStroke outboards.
Published fitment references support Mercury 5.7L V10 350-400HP Verado FourStroke applications.
Published serial-specific fitment references list 3B266064 and above.
Shipping
Ships as one Mercury 8M0228544 upper thermostat assembly.
Key Facts
Brand: Mercury
Part Number: 8M0228544
Product Type: Upper Thermostat Assembly
Engine Family: Mercury 5.7L V10 FourStroke outboards
Horsepower Range: 350-400HP
Published Verado Fitment: 350-400HP 5.7L V10 Verado
Published Serial Range: 3B266064 and up
Temperature Rating: 143 degrees F / 62 degrees C
Sold As: Individual unit
Quantity Required: 2 on supported applications
What’s Included
Included: One upper thermostat assembly
Included Part Number: 8M0228544
Not Included: Additional thermostat assembly required for engines that use two
Service Notes
Sold individually.
Two are required on published supported 5.7L V10 Verado applications.
Some published references show this part as superseding 8M0205186.
Some published retailer references also note one-time-use Oetiker clamps may be required during replacement.
Verify exact fitment by engine family, horsepower, serial number, and thermostat location before ordering.