8M0090819 Mercury MerCruiser Mercury Thermostat Assembly | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver 120°F Thermostat Assembly - Part Number: 8M0090819

Genuine Quicksilver 120°F thermostat and housing assembly used on Mercury 75HP to 115HP 2.1L FourStroke outboards. This assembly replaces / cross-references with 892864T06-style thermostat assemblies and is used on 65 Jet, 75HP, 90HP, 100HP and 115HP EFI FourStroke models where the cooling-system diagram specifies 8M0090819.

⚙️ Key Features

• Genuine Quicksilver OEM thermostat assembly

• Correct Mercury part number 8M0090819

• 120°F / approximately 50°C thermostat assembly

• Used on Mercury 75HP to 115HP 2.1L outboards

• Includes thermostat and housing assembly configuration

• Direct replacement for supported 2.1L EFI FourStroke cooling systems

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 8M0090819 current OEM thermostat and housing assembly reference

• 892864T06 earlier / related thermostat assembly reference where cross-listed

OEM / Related Numbers:

• 8M0090819

• 892864T06

• Mercury thermostat assembly

• 120°F thermostat assembly

• 50°C thermostat assembly

• 2.1L FourStroke thermostat housing

• Thermostat and housing assembly

• 25-8M0005958 related O-ring family reference

• 25-8M0153609 related grommet family reference

• 8M0204709 related water pump faceplate family reference

Aftermarket / Verified Equivalents:

• Aftermarket thermostat assembly replacements for 8M0090819 / 892864T06

• YM-8M0090819 aftermarket 50°C thermostat assembly equivalent

• Aftermarket Mercury 75HP-115HP 2.1L thermostat housing assemblies where matched by OEM number

• Use complete assembly match where the housing and thermostat are supplied together

🚤 Compatibility

Commonly used on:

• Mercury 75HP to 115HP 2.1L EFI FourStroke outboards

• Mercury SeaPro 75HP / 90HP / 115HP 2.1L cooling systems

• Thermostat service where housing assembly 8M0090819 is specified

Typically suits:

• Engine models:

• Mercury 65 Jet EFI 2.1L FourStroke - serial 2B095049 and up

• Mercury 75HP EFI FourStroke 2.1L - serial 2B095049 and up

• Mercury 75HP EFI SeaPro 2.1L - serial 2B095049 and up

• Mercury 90HP EFI FourStroke 2.1L - serial 2B095049 and up

• Mercury 90HP EFI SeaPro 2.1L - serial 2B095049 and up

• Mercury 100HP EFI FourStroke 2.1L - serial 2B095049 and up

• Mercury 115HP EFI FourStroke 2.1L - serial 2B095049 and up

• Mercury 115HP EFI Pro XS / SeaPro 2.1L applications where 8M0090819 is specified

• Mercury 75HP to 115HP 2.1L outboard cooling-system diagrams listing thermostat assembly 8M0090819

• HP Range: 65 Jet, 75HP, 90HP, 100HP and 115HP where specified

• Serial Range: commonly 2B095049 and up

• Engine Type: Mercury 2.1L EFI FourStroke outboard

• System Type: Thermostat and housing assembly

• Temperature Rating: 120°F / approximately 50°C

🔌 Function

The thermostat assembly regulates engine operating temperature by controlling cooling-water flow through the engine as it warms and operates under load.

Common signs of failure:

• Engine running too cold or too hot

• Overheat warning

• Temperature fault code

• Thermostat stuck open or closed

• Corrosion or salt deposits inside thermostat housing

• Cooling-system service requiring thermostat replacement

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging