Thermostat Kit 120° – Fits Mercury/Mariner 6-25 HP 2-Stroke (Replaces 14586A3, 75692A9)

Thermostat Kit 120° – Fits Mercury/Mariner 6-25 HP 2-Stroke (Replaces 14586A3, 75692A9)

This thermostat kit is designed for Mercury and Mariner 2-stroke outboard engines ranging from 6 HP to 25 HP, typically manufactured between 1986 and 1998+. It provides a reliable, direct-fit replacement for maintaining optimal engine operating temperature.

This kit replaces multiple OEM and aftermarket part numbers, including Mercury 14586A3, 75692A9, 75692A10, and 75692A11. See the cross-reference table for a complete list.

• Includes a 120°F (49°C) thermostat and all necessary gaskets for a complete service.
• Engineered for a direct replacement installation, matching OEM specifications.
• Maintains a nominal engine operating temperature of 120°F (49°C) for improved performance and longevity.

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.

Technical Specifications

Package Contents

This kit includes all necessary components for a complete thermostat replacement:

• 1 x Thermostat (Replaces 14586)
• 1 x Thermostat Seal/Ring Rubber (Replaces 62386001 / 27-62386)
• 1 x Thermostat Cover Gasket (Replaces 14318 / 27-14318-3)
• 1 x Thermostat Gasket (Replaces 19205 / 27-19205-1)

Installation Guide

1. Ensure the engine is completely cool before beginning. Disconnect the negative battery terminal for safety.
2. Locate the thermostat housing on the engine block or cylinder head. Place a drain pan underneath to catch any spilled coolant.
3. Carefully remove the bolts securing the thermostat housing cover. Note the orientation of the housing and hoses.
4. Gently pry the cover off. If it is stuck, tap it lightly with a rubber mallet.
5. Remove the old thermostat and the surrounding gaskets or seals. Note the thermostat's orientation.
6. Thoroughly clean the mating surfaces of the housing and its cover, removing all old gasket material and corrosion.
7. Install the new thermostat in the correct orientation.
8. Place the new gaskets and seals in their correct positions as specified by your engine's service manual.
9. Re-secure the housing cover and tighten the bolts to the manufacturer's recommended torque specification.
10. Reconnect any hoses, top off the engine coolant if necessary, and reconnect the battery terminal.
11. Start the engine and check for any leaks around the housing as it warms up to operating temperature.

Troubleshooting & FAQ

Q: How do I confirm this thermostat kit fits my engine?
A: The best way is to check the 'Compatible Engine Models' table on this page. Your engine's brand, model, HP, and especially the serial number must fall within the ranges listed. You should also verify that your original thermostat's part number is listed in our cross-reference table, such as 14586A3 or 75692A9.

Q: What are the common signs of a failing outboard thermostat?
A: Key signs include the engine overheating on the gauge despite a strong water stream from the tell-tale, or the engine running too cold and failing to reach proper operating temperature. Inconsistent temperature readings or alarms can also point to a thermostat that is stuck open or closed.

Q: How often should I replace my engine's thermostat?
A: For preventative maintenance, it is good practice to inspect your thermostat annually and replace it every 200-300 hours of operation or every 2-3 years. Replacement is especially important if you frequently operate in saltwater, as salt can accelerate corrosion and cause the thermostat to fail.

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.