130°F Thermostat for Force Outboards and Mercury SportJet – Replaces F664068
130°F Thermostat for Force Outboards and Mercury SportJet – Replaces F664068 is backordered and will ship as soon as it is back in stock.
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130°F Thermostat for Force Outboards and Mercury SportJet – Replace...
130°F Thermostat for Force Outboards and Mercury SportJet – Replaces F664068 is backordered and will ship as soon as it is back in stock.
Product Details
This 130°F thermostat is an aftermarket replacement for specified Force outboard engines and Mercury SportJet applications. It is designed to help maintain the engine’s intended operating temperature and replaces the original thermostat identified by Force part number F664068.
The company catalog identifies this product as a single thermostat rather than a multi-component kit. It is listed for selected Force 70–150 HP two-stroke applications, Mercury SportJet powerheads, and Force L-Drive models. Always compare the engine brand, horsepower, model year, and serial number with the fitment information before ordering.
- Thermostat rated at 130°F (approximately 54°C).
- Aftermarket replacement for specified Force and Mercury Mariner applications.
- Customer-facing cross-references include Force F664068, Mercury 859620, and Sierra 18-3527.
- Sold as one thermostat; a gasket, cover gasket, housing, or other service parts are not confirmed as included.
Part Number Matrix
These are the documented manufacturer and aftermarket reference numbers associated with this thermostat.
| Brand | Part Number | Reference Type |
|---|---|---|
| Force | F664068 | Replacement reference |
| Mercury | 859620 | Manufacturer reference |
| Sierra | 18-3527 | Aftermarket reference |
Engine & Model Compatibility
The fitment below is grouped by engine family, horsepower, stroke, and year or serial condition. The thermostat is not confirmed for every engine within a horsepower range. Match the complete application details before installation.
| Brand | Application | Rated HP | Stroke | Years | Reference | Notes |
|---|---|---|---|---|---|---|
| Force | Outboard | 70 | 2-Stroke | 1991–1995 | F664068 | Specified Force 70 HP application. |
| Force | Outboard | 75 | 2-Stroke | 1996–1999 | F664068 | Verify the engine model and serial number. |
| Force | Outboard | 85 | 2-Stroke | 1989 | F664068 | Specified Force 85 HP application. |
| Force | Outboard | 90 | 2-Stroke | 1991–1999 | F664068 | Verify the exact model and serial number. |
| Force | Outboard | 150 | 2-Stroke | 1989–1994 | F664068 | Specified Force 150 HP application. |
| Force | L-Drive | 85–125 | 2-Stroke | 1989–1994 | F664068 | Listed for Force L-Drive applications; confirm the complete model designation. |
Mercury SportJet Applications
| Brand | Application | Rated HP | Stroke | Years | Reference | Notes |
|---|---|---|---|---|---|---|
| Mercury SportJet | Jet-drive powerhead | 90 | 2-Stroke | 1993–1995 | F664068 | Specified 90 HP SportJet application. |
| Mercury SportJet | Jet-drive powerhead | 120 | 2-Stroke | 1995–1998 | F664068 | Specified 120 HP SportJet application. |
Technical Specs
- Product Type
- Single thermostat
- Installation
- Replacement thermostat for the original application
- Temperature Rating
- 130°F / approximately 54°C
- Primary Replacement Reference
- Force F664068
- Additional References
- Mercury 859620; Sierra 18-3527
- Application Type
- Selected Force outboards, Force L-Drive models, and Mercury SportJet applications
What’s in the Box
- 1 x Thermostat, 130°F / approximately 54°C
A gasket or cover gasket is not confirmed as included. Reuse is not recommended unless the existing gasket is specifically approved for reuse; obtain any required sealing components separately for your exact engine.
Installation Notes
- Confirm the engine model, horsepower, year, stroke, and serial number against the compatibility information before beginning work.
- Allow the engine to cool completely and follow the manufacturer’s service procedure.
- Disconnect the battery or follow the applicable safety isolation procedure.
- Locate the thermostat housing and place a suitable drain pan beneath the work area if water may be released when the housing is opened.
- Remove the thermostat housing cover and note the orientation of the old thermostat.
- Remove the old thermostat and inspect the housing, sealing surfaces, and related components for corrosion or damage.
- Clean the mating surfaces without gouging the housing.
- Install the new thermostat in the same orientation as the original part.
- Install a suitable new gasket or seal if required by the engine service procedure. The gasket is not confirmed as part of this product.
- Reinstall the housing cover and tighten the fasteners to the engine manufacturer’s specified torque.
- Run the engine according to the service manual and check for leaks, proper cooling-water flow, and normal operating temperature.
Troubleshooting & FAQ
How do I know if this thermostat fits my engine?
Match the engine brand, application, horsepower, two-stroke configuration, and model year shown in the compatibility tables. For Force 75 HP and 90 HP applications, and for any model with multiple production versions, verify the exact model and serial number before ordering.
Is this a kit or a single thermostat?
The company product record identifies this item as a single thermostat, even though some catalog labels use the term “thermostat kit.” Only one thermostat is confirmed in the box. Gaskets and other service parts are not confirmed as included.
What temperature is this thermostat?
This thermostat is specified at 130°F, approximately 54°C. The Fahrenheit and Celsius figures are rounded equivalents.
What are common signs of a thermostat problem?
A thermostat that remains open can allow the engine to run too cool, while one that remains closed can contribute to overheating. Abnormal temperature readings, an overheat warning, poor warm-up behavior, or restricted cooling-water flow should be diagnosed together with the water pump, passages, temperature sensor, and related components.
Does this thermostat include a gasket?
No gasket is confirmed as included with this product. Check the service parts for your exact engine and obtain the correct gasket or seal separately when required.
Is this an OEM thermostat?
This listing is for an aftermarket replacement thermostat. It is intended to replace the documented original application references, but it is not represented as a genuine OEM-branded part.
How often should an outboard thermostat be inspected?
Inspection intervals depend on the engine manufacturer’s maintenance schedule and operating conditions. Inspect the thermostat when servicing the cooling system and whenever the engine shows abnormal temperature behavior. Replace it if it is corroded, damaged, stuck, or outside the manufacturer’s specifications.
How fast is shipping and what does it cost?
Shipping availability, delivery estimates, and applicable charges are displayed at checkout based on the destination and selected service.
Safety & Important Info
- Verify the complete engine application and compare the replacement thermostat with the original part before installation.
- Do not rely on horsepower alone when multiple model years or serial ranges exist.
- This is an aftermarket replacement component, not a genuine OEM-branded part.
- Work only on a cool engine and follow the applicable manufacturer service manual.
- Professional installation is recommended if you are not familiar with outboard cooling-system service.
About Sea Sierra
- Marine-Focused Parts — We supply replacement components for marine maintenance and repair applications.
- Application-Based Listings — Product information is organized around documented engine and part-number references.
- Support for Correct Selection — Confirm the full model, year, horsepower, stroke, and serial conditions before ordering.
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