# 850055001 Mercury MerCruiser Thermostat 110 Mercury | Genuine Quicksilver OEM Part

🔧 Product Description

  

Genuine Quicksilver 110°F Thermostat - Part Number: 850055001

  

A genuine Quicksilver 110°F thermostat for selected Mercury and Mariner 3-cylinder 2-stroke outboards. This thermostat regulates cooling water temperature through the engine block, helping the engine reach and maintain correct operating temperature.

  

⚙️ Key Features

  

• Genuine Quicksilver OEM thermostat

• Correct Mercury part number 850055001

• 110°F / 43°C thermostat

• Used on selected Mercury / Mariner 40HP, 50HP, 55HP and 60HP 3-cylinder engines

• Helps maintain correct cooling system temperature and engine efficiency

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 850055001 current OEM thermostat reference

• 850055 related earlier OEM reference

  

OEM / Related Numbers:

  

• 850055001

• 850055

• 8500550014

• 27-827284 related thermostat gasket

  

Aftermarket / Verified Equivalents:

  

• Sierra: 18-3534

• Recmar: REC850055001

• Outboard Spares: OST850M

  

🚤 Compatibility

  

Commonly used on:

  

• Mercury / Mariner 3-cylinder 2-stroke cooling system thermostat applications

  

Typically suits:

  

• Engine models:

• Mercury / Mariner 40HP 3-cylinder 2-stroke, 1987-1998 applications where 850055001 is specified

• Mercury / Mariner 40HP 3-cylinder - serial 9973100 to 0P016999

• Mercury / Mariner 40HP 3-cylinder - serial 0P017000 to 0P325499

• Mercury / Mariner 40HP 3-cylinder - serial 0P325500 and up

• Mercury / Mariner 50HP 3-cylinder, 1986-2010 applications where 850055001 is specified

• Mercury / Mariner 50HP 3-cylinder - serial 9683055 to 9885344

• Mercury / Mariner 50HP 3-cylinder - serial 9885345 to 9973099

• Mercury / Mariner 50HP 3-cylinder - serial 0G760300 to 0T979999

• Mercury / Mariner 50HP 3-cylinder - serial 1B000001 and up

• Mercury / Mariner 55HP 3-cylinder applications where 850055001 is specified

• Mercury / Mariner 55HP 3-cylinder - serial 0G590000 to 0G760299

• Mercury / Mariner 55HP 3-cylinder - serial 0P017000 to 0P325499

• Mercury / Mariner 55HP 3-cylinder - serial 0T980000 and up

• Mercury / Mariner 60HP 3-cylinder, 1995-2014 applications where 850055001 is specified

• Mercury / Mariner 60HP 3-cylinder - serial 0D000750 to 0G290584

• Mercury / Mariner 60HP 3-cylinder - serial 0G590000 to 0G760299

• Mercury / Mariner 60HP 3-cylinder - serial 0P017000 to 0P325499

• Mercury / Mariner 60HP 3-cylinder - serial 0P325500 and up

• Mercury / Mariner 60HP 3-cylinder BigFoot - serial 0G760300 to 0T979999

  

• HP Range: 40HP - 60HP

• Engine Type: Mercury / Mariner 3-cylinder 2-stroke outboard

• Temperature Rating: 110°F / 43°C

  

🔌 Function

  

The thermostat controls cooling water flow to help the engine reach the correct operating temperature and avoid running too cold or overheating.

  

Common signs of failure:

  

• Engine overheating

• Engine runs too cold

• Temperature alarm at idle or under load

• Thermostat stuck open or closed

• Corrosion, salt build-up or debris around the thermostat seat

  

📦 Condition

  

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 76.25 AUD
- **Vendor:** Quicksilver
- **Tags:** Quicksilver Marine Parts | Oils Service Kits & Engine Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 76.25 AUD | In stock |

## Images

- 850055001 Mercury MerCruiser Thermostat 110 Mercury | Genuine Quicksilver OEM Part

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> Source: [Sawley's Auto and Marine](www.sawleysautoandmarine.com.au/products/850055001-mercury-mercruiser-thermostat-110-mercury-genuine-quicksilver-oem-part)
> Updated: 2026-05-17