# 833072003 Mercury MerCruiser Thermostat | Genuine Quicksilver OEM Part

🔧 Product Description

  

Genuine Quicksilver 143°F Thermostat - Part Number: 833072003

  

A genuine Quicksilver 143°F thermostat used on selected Mercury and Mariner OptiMax / DFI outboards. This thermostat regulates cooling water temperature in the engine cooling system and is commonly used on 2.5L DFI 135HP, 150HP and 175HP applications.

  

⚙️ Key Features

  

• Genuine Quicksilver OEM thermostat

• Correct Mercury part number 833072003

• 143°F / 62°C thermostat

• Used on selected Mercury / Mariner OptiMax and DFI engines

• Direct replacement for specified 2.5L DFI cooling system applications

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 833072003 current OEM thermostat reference

• 833072 related OEM thermostat reference

• 833072002 / 833072004 related thermostat references

  

OEM / Related Numbers:

  

• 833072003

• 833072

• 833072002

• 833072004

• 27-62386001

• 62981

• 66850

• 75692

• 75692B

• 814554001

• 814554T01

  

Aftermarket / Verified Equivalents:

  

• Sierra: 18-3536

• Sierra: 18-3537

  

🚤 Compatibility

  

Commonly used on:

  

• Mercury / Mariner OptiMax / DFI cooling system thermostat applications

  

Typically suits:

  

• Engine models:

• Mercury / Mariner V135 DFI 2.5L - 1998 and newer, serial 0G590000 and up

• Mercury / Mariner V150 DFI 2.5L - 1998 and newer, serial 0G590000 and up

• Mercury / Mariner V175 DFI 2.5L - 2001 and newer, serial 0T178500 and up

• Mercury / Mariner OptiMax 135HP applications where 833072003 is specified

• Mercury / Mariner OptiMax 150HP applications where 833072003 is specified

• Mercury / Mariner OptiMax 175HP applications where 833072003 is specified

• Mercury / Mariner OptiMax 75HP, 90HP, 115HP, 135HP, 150HP and 175HP cooling applications where the 143°F thermostat family is specified

  

• HP Range: commonly 135HP - 175HP 2.5L DFI, with broader OptiMax thermostat-family applications where specified

• Engine Type: Mercury / Mariner OptiMax / DFI outboard

• Temperature Rating: 143°F / 62°C

• System Type: Cooling system thermostat

  

🔌 Function

  

The thermostat regulates cooling water flow so the engine reaches and maintains correct operating temperature.

  

Common signs of failure:

  

• Engine overheating

• Engine running too cold

• Temperature alarm at idle or under load

• Thermostat stuck open or closed

• Corrosion, scale or debris around the thermostat seat

  

📦 Condition

  

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 90.9 AUD
- **Vendor:** Quicksilver
- **Tags:** Quicksilver Marine Parts | Oils Service Kits & Engine Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 90.90 AUD | In stock |

## Images

- 833072003 Mercury MerCruiser Thermostat | Genuine Quicksilver OEM Part

---

> Source: [Sawley's Auto and Marine](www.sawleysautoandmarine.com.au/products/833072003-mercury-mercruiser-thermostat-genuine-quicksilver-oem-part)
> Updated: 2026-05-17