60°C Thermostat for Yamaha F25 Four-Stroke Outboards – Replaces 6FM-12411-00
60°C Thermostat for Yamaha F25 Four-Stroke Outboards – Replaces 6FM-12411-00 is backordered and will ship as soon as it is back in stock.
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60°C Thermostat for Yamaha F25 Four-Stroke Outboards – Replaces 6FM...
60°C Thermostat for Yamaha F25 Four-Stroke Outboards – Replaces 6FM-12411-00 is backordered and will ship as soon as it is back in stock.
Product Details
This 60°C thermostat is designed for Yamaha F25 four-stroke outboard applications listed below. It begins opening at approximately 60°C (140°F) to help regulate engine operating temperature and support proper cooling-system performance.
The thermostat is a single replacement component and corresponds to Yamaha OEM reference 6FM-12411-00. Some parts catalogs list the same reference in the extended format 6FM-12411-00-00.
- 60°C (140°F) opening temperature.
- For specified Yamaha F25 four-stroke outboard models.
- Replacement thermostat for installation in the engine cooling system.
- One thermostat is supplied; gaskets and seals are not included unless separately specified.
Part Number Matrix
Use the references below when comparing the replacement part with your original thermostat.
| Brand | Part Number | Reference Type |
|---|---|---|
| Yamaha | 6FM-12411-00 | OEM reference |
| Yamaha | 6FM-12411-00-00 | Extended catalog format |
Engine & Model Compatibility
This listing covers the following Yamaha F25 four-stroke model designations. Confirm the complete model designation and the original thermostat reference before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Reference | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F25L | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25LMH | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25LW | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25LWH | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25LWT | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25SMH | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25SW | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
| Yamaha | F25SWH | 25 | 4-Stroke | Verify for your engine | 6FM-12411-00 | Verify the full model code. |
Technical Specs
- Product Type
- Thermostat
- Application
- Yamaha outboard cooling system
- Engine Family
- F25 four-stroke outboards
- Opening Temperature
- 60°C (140°F)
- OEM Reference
- 6FM-12411-00
- Extended Catalog Reference
- 6FM-12411-00-00
- Product Configuration
- Single thermostat
What’s in the Box
- 1 x 60°C thermostat
Gaskets, seals and other installation hardware are not included unless specifically stated in the order details.
Installation Notes
- Allow the outboard engine to cool completely before servicing the thermostat.
- Disconnect the battery or follow the safety procedure specified in the engine service manual.
- Locate the thermostat housing and remove the cover according to the applicable Yamaha service procedure.
- Note the original thermostat orientation before removal.
- Remove the old thermostat and clean the mating surfaces carefully. Do not damage the housing or sealing surface.
- Install the replacement thermostat in the same orientation as the original part.
- Install a suitable new gasket or seal if required. The gasket is not included with this thermostat.
- Reinstall the thermostat housing and tighten the fasteners to the torque specified in the engine service manual.
- Run the engine according to the service procedure and check for water leaks and normal cooling-system operation.
Troubleshooting & FAQ
What is the opening temperature of this thermostat?
This thermostat is specified to begin opening at 60°C (140°F).
Which outboards use this thermostat?
This listing covers Yamaha F25L, F25LMH, F25LW, F25LWH, F25LWT, F25SMH, F25SW and F25SWH four-stroke model designations. Confirm the full model code and original part reference before installation.
Is this a complete thermostat kit?
No. This product is a single thermostat. Gaskets, seals and additional hardware are not included unless separately specified.
How can I tell whether my thermostat needs replacement?
Possible symptoms include overheating, abnormal temperature behavior, reduced cooling performance or a thermostat that remains stuck open or closed. Diagnose the cooling system before replacing the component.
Does the thermostat replace Yamaha reference 6FM-12411-00?
Yes. This listing identifies Yamaha reference 6FM-12411-00. Parts catalogs may show the extended format 6FM-12411-00-00.
Should I replace the gasket at the same time?
Yes. A new gasket or seal should be used when required by the engine service procedure. It is not included with this thermostat.
Safety & Important Info
- Work only on a completely cool engine and follow the applicable Yamaha service instructions.
- Verify the complete engine model designation and original thermostat reference before ordering.
- Do not operate the engine if the thermostat housing leaks after installation.
- Professional installation is recommended if you are not familiar with outboard cooling-system service.
About Sea Sierra
- Marine replacement parts selected for practical outboard service applications.
- Clear part-number and fitment information to help with pre-purchase verification.
- Support for routine maintenance and replacement needs across marine systems.
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