Thermostat for Mercury/Mariner 40–60 HP Outboards, Serial 1C050252 & Up – Replaces 8M0117413, 8M0168892
Thermostat for Mercury/Mariner 40–60 HP Outboards, Serial 1C050252 & Up – Replaces 8M0117413, 8M0168892 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Thermostat for Mercury/Mariner 40–60 HP Outboards, Serial 1C050252 ...
Thermostat for Mercury/Mariner 40–60 HP Outboards, Serial 1C050252 & Up – Replaces 8M0117413, 8M0168892 is backordered and will ship as soon as it is back in stock.
Product Details
This replacement marine engine thermostat is intended for Mercury and Mariner outboards rated from 40 to 60 HP with serial numbers 1C050252 and up. It helps regulate engine operating temperature within the cooling system.
The thermostat is listed as replacing Mercury Marine part numbers 8M0117413 and 8M0168892. Sierra part number 18-3640 is also listed as a corresponding reference for this application.
- Application coverage: Mercury/Mariner 40–60 HP outboards.
- Serial-number condition: 1C050252 and higher.
- Designed as a replacement thermostat for the original cooling-system location.
- One thermostat is included; housing, gasket and other installation hardware are not included unless specifically shown or stated.
Part Number Matrix
Use the following references when comparing this thermostat with your existing part or service information.
| Brand | Part Number | Reference |
|---|---|---|
| Mercury Marine | 8M0117413 | Replacement reference |
| Mercury Marine | 8M0168892 | Replacement reference |
| Sierra | 18-3640 | Corresponding aftermarket reference |
Engine & Model Compatibility
Confirm both the horsepower rating and the complete serial number before ordering. The documented application is defined by the 40–60 HP range and serial number 1C050252 and up; the available product record does not further specify individual model years, EFI configuration or cylinder count.
| Brand | Application | Rated HP | Serial Condition | Stroke | Reference Part No. |
|---|---|---|---|---|---|
| Mercury / Mariner | Outboard | 40–60 HP | 1C050252 and up | Not specified in the company record | 8M0117413 / 8M0168892 |
Technical Specs
- Product Type
- Marine engine thermostat
- Application
- Mercury/Mariner 40–60 HP outboards
- Serial Range
- 1C050252 and up
- Purpose
- Cooling-system temperature regulation
- Temperature Rating
- 120°F / 49°C
- Installation
- Replacement in the original thermostat location
- Material
- Not specified in the available company product record
What’s in the Box
- 1 x 120°F / 49°C outboard thermostat
Gaskets, seals, thermostat housing components and other hardware are not listed as included. Confirm the contents against the product image and your service requirements before installation.
Installation Notes
- Verify the engine brand, horsepower rating and complete serial number before beginning work.
- Allow the engine to cool completely and follow the service procedure for your specific outboard.
- Disconnect the battery or follow the manufacturer’s safety procedure to prevent accidental starting.
- Locate the thermostat housing and place suitable protection beneath the work area.
- Remove the housing cover according to the manufacturer’s instructions.
- Remove the old thermostat and inspect the housing, sealing surfaces and related components.
- Clean the mating surfaces and install the replacement thermostat in the specified orientation.
- Install a new gasket or seal if required by the manufacturer’s service procedure. Gasket is not listed as included.
- Reinstall the housing cover and tighten all fasteners to the manufacturer’s specifications.
- Run the engine using the manufacturer’s recommended procedure and check for leaks and proper temperature regulation.
Troubleshooting & FAQ
How can I confirm this thermostat fits my engine?
Confirm that your Mercury or Mariner outboard is rated from 40 to 60 HP and has serial number 1C050252 or higher. Also compare the existing thermostat and reference numbers 8M0117413, 8M0168892 and Sierra 18-3640. If the horsepower or serial-number condition does not match, do not assume compatibility.
What is the thermostat temperature rating?
The company product record specifies a purpose rating of 120°F / 49°C.
What are common signs of a thermostat problem?
Possible symptoms include abnormal engine temperature, overheating, or an engine that does not reach its normal operating temperature. These symptoms can also result from other cooling-system problems, so inspect the complete system before replacing parts.
Does this listing include a gasket or thermostat housing?
No. The listed package is one thermostat. A gasket, housing or other installation hardware is not specified as included.
Can I install it myself?
Installation should be performed by someone familiar with outboard service procedures. Use the service information for your exact engine and follow all safety, sealing and torque requirements.
Is this an OEM Mercury component?
This listing is for a replacement thermostat. The Mercury part numbers shown are reference numbers for application and replacement comparison; the listing does not state that the supplied thermostat is a genuine Mercury-branded component.
How often should an outboard thermostat be replaced?
Replacement timing depends on the engine, operating conditions and maintenance findings. Inspect the thermostat when troubleshooting temperature-regulation problems or servicing the cooling system, and follow the maintenance schedule for your specific outboard.
What should I check before ordering?
Check the engine brand, horsepower, full serial number, existing thermostat dimensions and reference number. The documented fitment is 40–60 HP with serial number 1C050252 and up.
Safety & Important Information
- Verify the complete engine serial number and horsepower before purchase.
- Allow the engine to cool before removing the thermostat housing.
- Use the manufacturer’s service procedure for installation orientation, gasket replacement and fastener torque.
- Do not operate the engine if the cooling system leaks or temperature regulation is abnormal.
- This is a replacement thermostat; Mercury and Mariner names and part numbers are used only to identify the intended application and reference numbers.
About Sea Sierra
- Marine Parts Selection — Replacement components for outboard maintenance and repair.
- Application-Focused Listings — Product references and documented fitment are provided to help with part comparison.
- Service-Ready Information — Check your engine identification details and service requirements before installation.
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