# 5005440 Evinrude Johnson Thermostat | Genuine OEM BRP Outboard Part

🔧 Product Description

  

Genuine BRP Evinrude Johnson 143°F Thermostat Assembly - Part Number: 5005440

  

A genuine BRP cooling thermostat used across a broad selection of Johnson, Evinrude and E-TEC outboards.

  

The thermostat is calibrated to begin opening at approximately 143°F / 62°C. It regulates cooling-water flow so the engine reaches and maintains the temperature required for correct combustion, oiling and engine-management operation.

  

⚙️ Key Features

  

• Genuine BRP 143°F thermostat

• Correct OEM reference 5005440

• Broad two-stroke, E-TEC and selected four-stroke coverage

• Replaces numerous earlier OMC thermostat references

• Sierra and other aftermarket replacements available

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 5005440 → Replaces 0777260

• 5005440 → Replaces 0508626 and 0508620

• 5005440 → Replaces 0437414 and 0434841

• 5005440 → Replaces 0393659 and 0378065

  

OEM / Related Numbers:

  

• 5005440

• 0777260

• 0508626

• 0508620

• 0437414

• 0434841

• 0393659

• 0378065

• 8330720 related thermostat reference

  

Aftermarket / Verified Equivalents:

  

• Sierra: 18-3543

• OST: OST500

• Waterlong / aftermarket 5005440 thermostat

• Recmar-style replacements sold under 5005440 / 434841

  

🚤 Compatibility

  

Commonly used on:

  

• Small conventional Johnson and Evinrude outboards

• Crossflow V4 and V6 engines

• Evinrude E-TEC 40HP-250HP cooling systems

• Selected 9.9HP and 15HP four-stroke engines

  

Typically suits:

  

• Engine models:

• Selected 6HP-55HP Johnson and Evinrude two-strokes

• 9.9HP and 15HP four-strokes - approximately 1994-2001

• Crossflow V4 and V6 outboards

• Evinrude E-TEC 40HP-90HP

• Evinrude E-TEC 115HP-200HP

• Selected Evinrude E-TEC 225HP and 250HP engines

• Engines whose thermostat diagram specifies any superseded number above

  

• HP Range: Approximately 6HP - 250HP

• Engine Type: Two-stroke, E-TEC direct-injection or selected four-stroke outboard

• Year Range: Engine-model controlled

  

🔌 Function

  

The thermostat restricts cooling-water flow during warm-up and opens as the engine reaches operating temperature.

  

Common signs of failure:

  

• Engine runs too cold

• Engine overheats because the thermostat is stuck closed

• Poor idle and excessive carbon buildup

• Temperature alarms occur intermittently

• Thermostat is corroded or salt-encrusted

• Thermostat seal leaks

• Engine does not reach normal operating temperature

• Cylinder-head temperatures are uneven

  

📦 Condition

  

• Genuine BRP part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 58.01 AUD
- **Vendor:** BRP (Evinrude/Johnson)
- **Tags:** Evinrude Johnson Outboard Parts | BRP Marine Engine Parts & Components

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 58.01 AUD | In stock |

## Images

- 5005440 Evinrude Johnson Thermostat | Genuine OEM BRP Outboard Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/5005440-thermostat)
> Updated: 2026-07-12