140°F/60°C Outboard Thermostat – Suzuki DF/DT and Johnson/Evinrude 10–70 HP
140°F/60°C Outboard Thermostat – Suzuki DF/DT and Johnson/Evinrude 10–70 HP is backordered and will ship as soon as it is back in stock.
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140°F/60°C Outboard Thermostat – Suzuki DF/DT and Johnson/Evinrude ...
140°F/60°C Outboard Thermostat – Suzuki DF/DT and Johnson/Evinrude 10–70 HP is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket 140°F/60°C marine outboard thermostat is a replacement temperature-control component for selected Suzuki DF and DT outboard engines and Johnson/Evinrude outboards. It helps regulate cooling-system temperature by opening at approximately 60°C (140°F), supporting the engine's normal operating temperature.
The company catalog lists this thermostat for Suzuki outboards from 25 to 70 HP and for Johnson/Evinrude applications from 10 to 70 HP. Because fitment can vary by model, year, and serial number, confirm the original thermostat number and the complete engine model before ordering.
- 140°F/60°C rating: Designed for applications requiring a 60°C thermostat.
- Aftermarket replacement: Replaces the listed OEM and aftermarket reference numbers when the application matches.
- Cooling-system function: Helps maintain the intended operating temperature of a compatible marine outboard.
- Single thermostat: This listing is for one thermostat, not a multi-piece kit.
Part Number Matrix
Use the following numbers as reference points and verify the number against your engine or service documentation before purchase.
| Brand or Reference | Part Number |
|---|---|
| Johnson/Evinrude/OMC | 5031758 |
| Johnson/Evinrude | 0769184 |
| Suzuki | 17670-94400 / 17670-94401 / 17670-94402 |
| Suzuki | 17670-94403 / 17670-94404 |
| Aftermarket reference | 18-S944 |
Engine & Model Compatibility
The company catalog identifies the following Suzuki model families and power ranges. Model suffixes, production years, and serial-number limits can affect fitment, so use the part-number cross-reference as well as the model information.
| Brand | Model Family | Rated HP | Stroke or Application | Documented Year Information |
|---|---|---|---|---|
| Suzuki | DF9.9, DF15 | 9.9–15 | Four-stroke applications | DF applications listed from 1996–2011 in the company notes |
| Suzuki | DF25, DF30 | 25–30 | Four-stroke applications | DF25/DF30 applications listed for 2000–2006 |
| Suzuki | DF40, DF50 | 40–50 | Four-stroke applications | DF40/DF50 applications listed for 1999–2010 |
| Suzuki | DF60, DF70 | 60–70 | Four-stroke applications | DF60/DF70 applications listed for 1998–2009 |
| Suzuki | DT9.9, DT15, DT20 | 9.9–20 | Two-stroke applications | Applications listed for 1986–2004 |
| Suzuki | DT25, DT30 | 25–30 | Two-stroke applications | Applications listed for 1986–2002 |
| Suzuki | DT40 | 40 | Two-stroke applications | Applications listed for 1986–2004 |
| Johnson/Evinrude | Selected outboard models | 10–70 | Application-specific; catalog evidence includes two-stroke models | Verify exact model, year, and serial number |
Technical Specifications
- Product Type
- Marine outboard engine thermostat
- Temperature Rating
- 140°F (60°C)
- Opening Temperature
- Approximately 140°F (60°C)
- Application Range
- Selected Suzuki, Johnson, and Evinrude outboard applications from 10 to 70 HP
- Product Construction
- Aftermarket replacement component
What's in the Box
- 1 x 140°F/60°C thermostat
A housing gasket is not listed as included. Reuse or replacement of the gasket should be determined during installation, and a new gasket is recommended when required by the engine manufacturer.
Installation Notes
- Allow the engine to cool completely before beginning work.
- Disconnect the battery or follow the engine manufacturer's safety procedure.
- Locate the thermostat housing and place a suitable drain pan beneath the work area.
- Remove the housing cover carefully and note the original thermostat orientation.
- Remove the old thermostat and clean the mating surfaces without damaging the housing.
- Install the new thermostat in the same orientation as the original part.
- Install a suitable new housing gasket if required, then refit the cover and tighten the fasteners to the manufacturer's specification.
- Restore the cooling system as required, start the engine, and check for leaks and proper water flow.
- Confirm that the engine reaches its normal operating temperature during a controlled test.
Troubleshooting & FAQ
What does the 140°F/60°C rating mean?
It identifies the approximate temperature at which the thermostat begins to open and regulate cooling-system flow for a compatible engine.
Is this an OEM thermostat?
No. This is an aftermarket replacement thermostat intended for applications that cross-reference to the listed OEM numbers.
Does the package include a gasket?
No gasket is listed as included. Check the condition of the existing gasket and the engine manufacturer's service instructions before installation.
Will it fit every Suzuki, Johnson, or Evinrude engine from 10 to 70 HP?
No. The stated horsepower range is an application guide, not a universal fitment claim. Verify the exact model, year, serial number, stroke, and original thermostat part number before ordering.
Why should I verify the original part number?
Thermostat fitment can change between model versions and serial-number ranges even when horsepower is the same. Matching the original number is the safest way to confirm compatibility.
What are common signs of a thermostat problem?
Possible symptoms include overheating, running below normal temperature, unstable temperature behavior, or reduced cooling-system performance. Inspect the complete cooling system before replacing the thermostat.
Safety & Important Information
- Verify the original thermostat number and complete engine identification before purchase.
- Keep model, year, serial number, horsepower, and stroke information together when checking fitment.
- Never work on a hot engine or open a pressurized cooling-system component while hot.
- This is an aftermarket replacement component and is not manufactured by Suzuki, Johnson, Evinrude, or OMC.
- Professional installation is recommended when the required service procedure or torque specifications are unfamiliar.
About Sea Sierra
- Marine Replacement Parts — We provide aftermarket components for maintenance and repair of marine engines and systems.
- Application-Focused Cataloging — Product references are presented to help customers compare OEM numbers and engine applications.
- Support for Fitment Checks — When model and part-number information is available, confirm those details before ordering to reduce compatibility errors.
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