130°F (54°C) Thermostat for Mercury 200–250 HP 3.0L DFI/EFI Outboards – Replaces 885599004, 8M0057307
130°F (54°C) Thermostat for Mercury 200–250 HP 3.0L DFI/EFI Outboards – Replaces 885599004, 8M0057307 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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130°F (54°C) Thermostat for Mercury 200–250 HP 3.0L DFI/EFI Outboar...
130°F (54°C) Thermostat for Mercury 200–250 HP 3.0L DFI/EFI Outboards – Replaces 885599004, 8M0057307 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket 130°F (54°C) thermostat is designed for selected Mercury and Mariner 200–250 HP 3.0L outboard applications. It is listed for 2-stroke DFI and EFI platforms and is intended to help maintain the engine’s specified operating temperature.
This thermostat replaces Mercury Marine OEM reference 885599004. Catalog references also associate it with 8M0057307 and Sierra 18-3535. Confirm the exact engine model, stroke, and serial-number range before ordering.
- 130°F (54°C) thermostat opening temperature.
- Aftermarket replacement for the listed Mercury Marine applications.
- Helps regulate engine temperature during normal operation.
- Sold as one thermostat; gasket is not included unless specifically stated.
Part Number Matrix
Use these references to compare the replacement with the part removed from your engine.
| Brand or Source | Reference | Relationship |
|---|---|---|
| Mercury Marine | 885599004 | OEM replacement reference |
| Mercury Marine | 8M0057307 | Catalog reference |
| Sierra | 18-3535 | Aftermarket interchange reference |
Engine & Model Compatibility
The following applications are taken from catalog fitment information for the 130°F thermostat reference. Model, stroke, and serial-number conditions must be considered together. A model name or horsepower rating alone does not confirm fitment.
| Brand | Model | Rated HP | Stroke | Year or Serial Condition | Reference |
|---|---|---|---|---|---|
| Mercury | 200 3.0L DFI DTS | 200 | 2-Stroke | All | 885599004 |
| Mercury | 200 DFI 3.0L | 200 | 2-Stroke | 1997 and newer; serial OG386496 and newer | 885599004 |
| Mercury | 200 3.0L EFI | 200 | 2-Stroke | 2003 and newer; serial OT750164 and newer | 885599004 |
| Mercury | 225 3.0L EFI | 225 | 2-Stroke | 1999 and newer; serial OG760300 and newer | 885599004 |
| Mercury | 225 3.0L EFI SeaPro | 225 | 2-Stroke | 2004 and newer; serial OT801000 and newer | 885599004 |
| Mercury | 225 3.0L DFI DTS | 225 | 2-Stroke | 2003 and newer; serial OT599000 and newer | 885599004 |
| Mercury | 225 DFI | 225 | 2-Stroke | 1998 and newer; serial OG590000 and newer | 885599004 |
| Mercury | 250 3.0L EFI | 250 | 2-Stroke | 1999 and newer; serial OG760300 and newer | 885599004 |
| Mercury | 250 Long 3.0L EFI | 250 | 2-Stroke | Serial OT861319 and newer | 885599004 |
Technical Specs
- Product Type
- Outboard engine thermostat
- Opening Temperature
- 130°F (54°C)
- Application
- Selected Mercury and Mariner 200–250 HP 3.0L 2-stroke DFI/EFI outboards
- Product Format
- Single thermostat
- Construction
- Aftermarket replacement
What’s in the Box
- 1 x 130°F (54°C) thermostat
Not included: Housing gasket or other installation hardware unless separately stated in the order details.
Installation Notes
- Turn off the engine, allow it to cool completely, and follow the manufacturer’s safety procedures.
- Verify the replacement against the thermostat removed from the engine, including physical dimensions and orientation.
- Locate the thermostat housing and remove the cover carefully, keeping track of the original fasteners.
- Remove the old thermostat and note its installed orientation before disposal.
- Clean the housing and cover mating surfaces without damaging them.
- Install the replacement thermostat in the same orientation as the original part.
- Install a new housing gasket if required; the gasket is not included with this thermostat.
- Reinstall the cover and tighten the fasteners evenly to the engine manufacturer’s specification.
- Run the engine according to the manufacturer’s procedure and check for leaks and proper water flow.
Troubleshooting & FAQ
How do I know if my thermostat may be failing?
Possible symptoms include overheating, an engine that runs unusually cool, inconsistent temperature behavior, or reduced cooling-system performance. These symptoms can also have other causes, so inspect the complete cooling system before replacing the thermostat.
Does this thermostat include a gasket?
No. This listing is for one thermostat. A housing gasket is not included unless specifically stated in the order details. Installing a new gasket is recommended when the housing is opened.
Will this fit both 2-stroke and 4-stroke engines?
The catalog fitment available for this 130°F replacement identifies selected 3.0L 2-stroke DFI and EFI Mercury applications. Do not assume fitment for 4-stroke engines. Verify the exact model and serial-number range before ordering.
What is the thermostat’s opening temperature?
This thermostat is specified to open at 130°F (54°C).
Is this an OEM part?
No. This is an aftermarket replacement. Mercury Marine references are provided for identification and compatibility comparison only.
What should I check before ordering?
Compare the thermostat with your original part and verify the complete engine model, horsepower, stroke, year, and serial-number condition. If any of these details differ, consult the engine manufacturer’s parts information before purchase.
Safety & Important Information
- Never work on a hot engine or cooling system.
- Confirm fitment using the complete model and serial-number information, not horsepower alone.
- Inspect the housing, gasket surface, and related cooling-system components during installation.
- This is an aftermarket replacement and is not manufactured by Mercury Marine.
- Professional installation is recommended when the correct procedure or torque specifications are unavailable.
About Sea Sierra
- Marine Replacement Parts — We supply aftermarket components for maintenance and repair applications.
- Application-Focused Listings — Product references and fitment conditions are provided to help support part identification.
- Customer Support — Contact support with your engine model and serial information if you need help comparing the replacement.
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