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)

This aftermarket thermostat is engineered to regulate engine temperature for select Mercury Marine 6-15 HP 2-Stroke outboards (1986-2005) and specific Johnson/Evinrude 4-Stroke engines. It ensures your engine operates within the optimal temperature range for performance and longevity.

This component is a direct replacement for Mercury OEM parts 14586, 14586A3, 75692A9, 75692A10, and 75692A11, as well as several aftermarket equivalents.

• Operating Temperature: Opens at 120°F (48.9°C)
• Installation Method: Direct Replacement
• Materials: Constructed from high-quality brass with stainless steel components for corrosion resistance.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

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.

Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.

Mercury Marine

Technical Specifications

Package Contents

• 1 x Thermostat (14586)

Note: When purchasing a complete thermostat kit (such as Sierra 18-43052), additional components like seals and gaskets are typically included. This listing is for the thermostat only.

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is cool before starting.
2. Drain Coolant: Drain the engine's cooling system to prevent spills.
3. Locate Housing: Find the thermostat housing on the engine block or cylinder head.
4. Remove Cover: Carefully unbolt and remove the thermostat housing cover.
5. Remove Old Thermostat: Take out the old thermostat and the corresponding gasket or seal.
6. Clean Surfaces: Thoroughly clean the mating surfaces of the housing and cover, removing any old gasket material.
7. Install New Thermostat: Place the new thermostat into the housing, ensuring it is oriented correctly. Install the new gasket/seal.
8. Reassemble: Securely fasten the housing cover. Do not overtighten the bolts.
9. Refill & Check: Refill the cooling system. Start the engine and carefully check for leaks around the housing as the engine warms up.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my specific Mercury engine?

A: Verify that your engine is a 2-stroke model between 6-15 HP, manufactured from 1986-2005. The most reliable method is to cross-reference the OEM part number (e.g., 14586) from your old thermostat or service manual with the numbers listed in our cross-reference table.

Q: What are common signs that my outboard's thermostat is failing?

A: Key symptoms include the engine overheating at low speeds, running too cold (failing to reach operating temperature), or erratic readings on the temperature gauge. A thermostat stuck open will cause the engine to run cold, while one stuck closed will cause it to overheat.

Q: Is the housing or gasket included with this part?

A: No, this listing is for the thermostat only. The housing assembly and gaskets must be sourced separately or reused if they are in good condition. We recommend replacing gaskets during installation to ensure a proper seal.

Q: OEM vs. Aftermarket?

A: 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.

Q: How fast do you ship and how much does it cost?

A: 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.

Q: What is your warranty and return policy?

A: 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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.