Thermostat with Housing for Mercury Mariner Verado 135–300 HP (Replaces 892864T04 / 8M0174561)
Thermostat with Housing for Mercury Mariner Verado 135–300 HP (Replaces 892864T04 / 8M0174561) is backordered and will ship as soon as it is back in stock.
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Thermostat with Housing for Mercury Mariner Verado 135–300 HP (Repl...
Thermostat with Housing for Mercury Mariner Verado 135–300 HP (Replaces 892864T04 / 8M0174561) is backordered and will ship as soon as it is back in stock.
Product Details
This thermostat with housing is a replacement cooling-system assembly for selected Mercury Mariner Verado outboard engines rated from 135 HP through 300 HP. It combines the thermostat and housing in one service part to help regulate engine operating temperature.
The assembly replaces Mercury Marine part numbers 892864T04 and 8M0174561. Sierra Marine reference 18-3631 is listed for a thermostat with housing matching this application.
- Replacement thermostat and housing assembly.
- Designed for selected Mercury Mariner Verado 135–300 HP applications.
- Thermostat operating temperature: 143°F (62°C).
- Confirm the engine model and serial number before ordering.
Part Number Matrix
Use the following references to compare the listed assembly with your original part.
| Brand | Part Number | Reference |
|---|---|---|
| Mercury Marine | 892864T04 | Replacement reference |
| Mercury Marine | 8M0174561 | Replacement/current reference listed for the thermostat assembly |
| Sierra Marine | 18-3631 | Thermostat with housing reference |
Engine & Model Compatibility
This assembly is listed for selected Mercury Mariner Verado 135–300 HP outboard engines. The exact fit can depend on the engine model and serial-number range, so compare your original part and verify the serial number before installation.
| Brand | Engine Family | Rated HP | Stroke | Fitment Note |
|---|---|---|---|---|
| Mercury Mariner | Verado | 135 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 150 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 175 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 200 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 225 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 250 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 275 HP | 4-Stroke | Verify model and serial number |
| Mercury Mariner | Verado | 300 HP | 4-Stroke | Verify model and serial number |
Technical Specs
- Product Type
- Thermostat with housing assembly
- Application
- Mercury Mariner Verado outboard engines
- Rated Engine Range
- 135–300 HP
- Thermostat Temperature
- 143°F (62°C)
- Replacement References
- Mercury Marine 892864T04 and 8M0174561
- Aftermarket Reference
- Sierra Marine 18-3631
What’s in the Box
- 1 × Thermostat with housing assembly
Note: Separate seals, clamps, and other hardware are not specified as included with this product. Reuse or replacement of installation hardware should follow the engine manufacturer’s service instructions.
Installation Notes
- Allow the engine to cool completely before beginning service.
- Disconnect the battery and follow the engine manufacturer’s safety procedures.
- Close or disconnect the appropriate water supply and remove the components necessary to access the thermostat housing.
- Disconnect the hoses and remove the original thermostat housing, noting the orientation of the original assembly.
- Clean the mating surfaces and inspect the hoses, clamps, and sealing surfaces for damage.
- Install the replacement thermostat with housing using the correct seals and hardware for your specific engine.
- Tighten fasteners to the manufacturer-specified torque; do not guess at torque values.
- Reconnect the hoses and confirm that all clamps are secure.
- Restore the cooling-water supply, start the engine, and check for leaks and abnormal temperature indications.
- Complete the installation according to the applicable Mercury service procedure.
Troubleshooting & FAQ
What does this product include?
This listing is for one thermostat with housing assembly. A separate O-ring, clamp, or additional installation hardware is not specified as included.
What engines does this thermostat with housing fit?
The company fitment record lists Mercury Mariner Verado engines from 135 HP through 300 HP. Because Verado applications vary by model and serial number, verify the exact engine identification and compare the original part before ordering.
What temperature is this thermostat designed for?
The listed thermostat temperature is 143°F (62°C).
Which part numbers does it replace?
The listed Mercury Marine replacement references are 892864T04 and 8M0174561. Sierra Marine reference 18-3631 is also associated with a thermostat with housing.
Can I install it on a non-Verado Mercury engine?
Do not assume compatibility with non-Verado engines. The documented application is Mercury Mariner Verado 135–300 HP; verify the model and serial number before installation.
Should the old seal or clamp be reused?
Inspect all sealing components and clamps during service. Replace damaged, hardened, or otherwise unsuitable parts and follow the service instructions for the specific engine.
How quickly will the order ship?
Shipping methods, delivery estimates, and available expedited options are shown at checkout based on the destination and selected service.
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