Thermostat Kit (160°F) – Fits Mercruiser 4.3L-8.2L SternDrive Motors (Replaces 807252Q5, 807252T8, 8M0091470)

Thermostat Kit (1606F) Fits Mercruiser 4.3L-8.2L SternDrive Motors (Replaces 807252Q5, 807252T8, 8M0091470)

This thermostat kit is designed for use with Mercury/Mercruiser 4.3L, 5.0L, 5.7L, 7.4L, and 8.2L V6 & V8 SternDrive engines produced from 1987 to 2016. It fits a wide range of models within these engine series, providing reliable temperature regulation.

The kit is a direct replacement for Mercruiser part numbers 807252Q5, 807252T8, 8M0091470, and 8M0109441 as well as Sierra 18-3647, GLM 13101, and Mallory 9-43157, ensuring compatibility across multiple aftermarket brands.

• Includes thermostat, gaskets, O-ring, and housing sleeve
• Designed for direct replacement installation
• Operates at a temperature rating of 1606F (716C)

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, heres a guide to help you identify your engines serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1  Thermostat 1606F (807252T2/808252)
• 1  O-ring (25-30224)
• 1  Gasket (27-33179-2)
• 1  Gasket (27-47510)
• 1  Housing Sleeve (806922/23-806922)
• 1  Gasket (27-48818-1)
• 1  Gasket (27-33918)

Installation Guide

1. Ensure the engine is cool and disconnect the battery before starting installation.
2. Drain the cooling system to prevent spills when removing the old thermostat.
3. Remove the thermostat housing carefully, noting the orientation of the thermostat.
4. Take out the old thermostat and clean the housing surface thoroughly.
5. Install the new thermostat and included gaskets and O-rings as per the kit instructions.
6. Reattach the thermostat housing and tighten bolts securely but do not over-torque.
7. Refill the cooling system with the appropriate coolant.
8. Reconnect the battery and start the engine to check for leaks and proper thermostat operation.
9. Allow the engine to reach operating temperature to verify the thermostat opens correctly at 1606F.
10. If leaks or issues are found, power down the engine and recheck the installation steps.

Troubleshooting & FAQ

• How do I confirm this fits my engine? Confirm your engine model and production years match the compatibility table. You can also verify using OEM part numbers and engine serial/model guides.
• What are the differences versus OEM parts? This listing is an aftermarket replacement part, built to OEM specifications with comparable-grade materials from an ISO9002-certified facility. Each batch undergoes inspection to ensure consistent performance.
• How often should I replace the thermostat? Replacement depends on engine usage and conditions, but typically a thermostat should be inspected regularly and replaced if signs of failure or poor regulation occur.
• What are common signs of thermostat failure? Engine overheating, inconsistent temperature readings, or coolant leaks around the thermostat housing can indicate a faulty thermostat.
• 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 shipping15 days worldwide15 days worldwide typical 515 days worldwide; 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 exist15 days worldwide, even if your model is listed15 days worldwide, 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 515 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.