Mercury Verado Thermostat Housing & Thermostat – Fits L6 200-400 HP
This thermostat and housing assembly is designed for Mercury 200-400 HP Verado L6 (6-cylinder) outboards manufactured between 2004 and 2018. It serves as a direct-fit replacement for the original component, ensuring proper engine temperature regulation.
Engineered to meet or exceed OEM specifications, this assembly restores cooling system performance, preventing overheating or overcooling issues. It is a complete unit that includes both the thermostat and the housing.
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Installation Method: Direct bolt-on replacement.
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Key Component: Includes pre-installed thermostat set to open at approximately 60°C (140°F).
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Required for Installation: A new one-time-use hose clamp (Mercury part No. 850896) is required.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
Superseded By |
| Mercury |
892864T04 |
8M0174561 |
| WSM |
775-60 |
|
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Mercury |
Verado L6 |
200 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
225 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
250 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
275 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
300 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
350 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
400 |
4-Stroke |
2004-2018 |
892864T04 |
Also fits supercharged models |
| Mercury |
Verado L6 |
400R |
4-Stroke |
2004-2018 |
892864T04 |
Also fits racing models |
Technical Specifications
| Specification |
Value |
| Product Type |
Outboard Thermostat with Housing |
| Installation |
Direct bolt-on replacement |
| Connection |
Hose connection with clamp |
| Housing Material |
Metal/brass |
| Housing Color |
Silver/brass |
| Fitting Type |
Hose connection |
| Operating Temperature |
Approximate opening temperature: 60°C (140°F) |
| Other Technical Attributes |
Located on top of cylinder head, requires one-time-use hose clamp (Mercury part No. 850896) for installation |
Package Contents
- 1 x Thermostat Housing Assembly with Thermostat (Replaces OEM Part 892864T04)
Installation Guide
Follow these steps for a proper installation. Ensure the engine is completely cool before starting.
- Locate the thermostat housing, which is situated on top of the engine's cylinder head.
- Carefully remove the old hose clamp connecting the coolant hose to the housing.
- Unbolt and remove the old thermostat housing assembly from the cylinder head.
- Thoroughly clean the mating surface on the cylinder head to ensure there is no old gasket material or corrosion.
- Position the new thermostat and housing assembly onto the cylinder head.
- Tighten the mounting bolts evenly to the manufacturer-specified torque to ensure a good seal.
- Reconnect the coolant hose to the new housing using a new one-time-use hose clamp (Mercury part No. 850896).
- Check and refill the engine coolant to the appropriate level.
- Start the engine, let it idle, and carefully check for any coolant leaks around the new housing and hose connection.
Troubleshooting & FAQ
How do I confirm this part fits my specific Verado engine?
First, check the "Compatible Engine Models" table on this page. Then, use the provided Mercury Serial Number Guide to verify your engine's model and year matches the compatibility list. Cross-referencing the part number (892864T04) is the best way to guarantee fitment.
What are the signs of a faulty thermostat?
Common symptoms include the engine overheating at idle or low speeds, or the engine failing to reach its normal operating temperature. An alarm from the engine's monitoring system may also indicate a cooling issue related to the thermostat.
How often should I replace the thermostat on my Mercury Verado?
It is recommended to inspect and potentially replace the thermostat as part of your regular engine maintenance schedule. Many technicians suggest replacement every 300 hours or every 3 years, whichever comes first, to prevent cooling system failures.
OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.