Outboard Thermostat – Fits Mercury Marine 6-15 HP Two-Stroke Outboards (Replaces 14586)
Outboard Thermostat – Fits Mercury Marine 6-15 HP Two-Stroke Outboards (Replaces 14586) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Outboard Thermostat – Fits Mercury Marine 6-15 HP Two-Stroke Outboa...
Outboard Thermostat – Fits Mercury Marine 6-15 HP Two-Stroke Outboards (Replaces 14586) is backordered and will ship as soon as it is back in stock.
Product Details
This is a replacement Outboard Thermostat designed for Mercury Marine 6–15 HP two-stroke outboard engines manufactured between 1986 and 2005. It ensures your engine maintains the correct operating temperature for optimal performance and longevity. It also fits specific Johnson/Evinrude four-stroke engines that use the corresponding OEM part numbers.
This component serves as a direct replacement for Mercury part numbers 14586, 14586A3, 75692A9, 75692A10, and 75692A11, and interchanges with Sierra 18-3549, GLM 13120/13130, Mallory 9-43014, and AM435491.
- Installation Method: Direct replacement for a hassle-free fit.
- Operating Temperature: Opens at 120°F (48.9°C) to regulate engine temperature.
- Durable Materials: Constructed from high-quality brass and stainless steel components for corrosion resistance in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury Marine | 14586 |
| Mercury Marine | 14586A3 |
| Mercury Marine | 75692A9 |
| Mercury Marine | 75692A10 |
| Mercury Marine | 75692A11 |
| Johnson/Evinrude | 435491 |
| Johnson/Evinrude | 0435491 |
| Johnson/Evinrude | 0765559 |
| Sierra | 18-3549 |
| GLM | 13120 |
| GLM | 13130 |
| Mallory | 9-43014 |
| AM | AM435491 |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
This thermostat is confirmed to fit the following Mercury Marine two-stroke outboard motors.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Mercury | 2-Stroke Outboards | 6 | 2-Stroke | 1986–2005 | 14586 |
| Mercury | 2-Stroke Outboards | 7 | 2-Stroke | 1986–2005 | 14586 |
| Mercury | 2-Stroke Outboards | 8 | 2-Stroke | 1986–2005 | 14586 |
| Mercury | 2-Stroke Outboards | 9.9 | 2-Stroke | 1986–2005 | 14586 |
| Mercury | 2-Stroke Outboards | 15 | 2-Stroke | 1986–2005 | 14586 |
Technical Specs
- Product Type
- Outboard Engine Thermostat
- Installation
- Direct Replacement
- Temperature Rating
- 120°F (48.9°C)
- Material
- Brass with stainless steel components
- Housing Compatibility
- Requires separate housing assembly (not included)
- Operating Temperature
- 120°F (48.9°C) opening temperature
- Certification
- Manufactured in an ISO9002 certified factory
What’s in the Box
- 1 x Thermostat (Replaces 14586)
Installation Notes
- Disconnect the negative battery cable for safety.
- Allow the engine to cool completely before starting.
- Locate the thermostat housing on the engine block or cylinder head.
- Place a drain pan underneath and carefully remove the housing cover bolts and cover.
- Note the orientation of the old thermostat before removing it. Remove the old gasket or seal.
- Thoroughly clean both the housing and cover mating surfaces to remove any old gasket material or corrosion.
- Install the new thermostat in the correct orientation.
- Install the new thermostat gasket/seal (sold separately).
- Reinstall the housing cover and tighten the bolts to the manufacturer's specified torque.
- Reconnect the battery cable, start the engine, and carefully check for any coolant leaks around the housing.
Troubleshooting & FAQ
How do I know if my thermostat is failing?
Common signs of a faulty thermostat include the engine overheating at low speeds, the engine temperature gauge reading higher or lower than normal, or the engine not reaching its proper operating temperature. This can lead to poor performance, increased fuel consumption, or engine damage.
Is a gasket included with this thermostat?
No, this listing is for the thermostat only. The required gaskets and seals must be purchased separately or as part of a complete thermostat kit (such as Sierra 18-43052).
Will this fit my Johnson/Evinrude engine?
This thermostat is listed as an interchange for OEM parts 435491, 0435491, and 0765559, which are used on some Johnson/Evinrude 4-stroke models. However, you must verify the exact part number required for your specific engine model and year before ordering, as compatibility can vary.
OEM vs. Aftermarket?
This listing is an aftermarket replacement, not an OEM (Original Equipment Manufacturer) part. It is built to meet or exceed OEM-level specifications using comparable high-quality materials. It is manufactured in an ISO 9002 certified facility and is batch-inspected to ensure quality and consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most regions, with expedited options available at checkout where applicable.
Warranty & returns
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. See our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world reliability in harsh marine conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions with an average transit time of 5–15 days, getting you back on the water sooner.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials, quality control, or performance.
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