Thermostat Housing Assembly – Fits Mercury/Mariner 75-150 HP 4-Stroke EFI Outboards (Replaces 892864T06, 8M0090819, 892864A06)

Thermostat Housing Assembly – Fits Mercury/Mariner 75-150 HP 4-Stroke EFI Outboards

This thermostat housing assembly is a direct-fit replacement for specified Mercury and Mariner 75-150 HP 4-Stroke EFI outboard models. It is designed to restore proper engine operating temperature by replacing a cracked, leaking, or faulty housing and thermostat.

This unit is a direct replacement for Mercury OEM part numbers 892864T06, 8M0090819, and 892864A06. It also cross-references with Sierra parts 18-3633, 18-3635, 18-3635-K, and GLM 13612.

• Complete assembly includes the housing, 48.8°C/50°C (120°F) thermostat, O-ring, and clamp.
• Engineered for a direct, bolt-on installation with no modifications required.
• Constructed from marine-grade materials to resist corrosion in freshwater and saltwater environments.

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

• 1 x Thermostat Housing Assembly (Replaces 892864T06)
• 1 x Thermostat (pre-installed in housing)
• 1 x O-ring seal (8M005958)
• 1 x Clamp (888988008)

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is completely cool.
2. Drain Coolant: Place a container under the engine and drain the cooling system to a level below the thermostat housing.
3. Locate Housing: Identify the thermostat housing on the engine block.
4. Disconnect Hoses: Loosen the hose clamps and carefully twist to remove the coolant hoses attached to the housing.
5. Remove Old Assembly: Unbolt and remove the old thermostat housing assembly from the engine.
6. Clean Surface: Thoroughly clean the engine's mounting surface, removing any old gasket material or corrosion.
7. Position New Assembly: Place the new O-ring/gasket in its groove and position the new housing assembly onto the engine.
8. Secure Bolts: Hand-tighten the mounting bolts, then torque them to the manufacturer's specifications.
9. Reconnect Hoses: Re-attach the coolant hoses and secure them with the clamps.
10. Refill Coolant: Refill the cooling system with the appropriate coolant mixture.
11. Final Checks: Reconnect the battery. Start the engine and let it run, carefully checking for any leaks around the housing and hoses.

Troubleshooting & FAQ

Q: How do I confirm this fits my engine?
A: The most reliable way is to verify your engine's serial number falls within the ranges listed in the compatibility table. For Mercury/Mariner outboards, the serial number is critical for confirming an exact match.

Q: What are common signs of a failing thermostat or housing?
A: Common symptoms include engine overheating, an engine that doesn't reach normal operating temperature, visible coolant leaks from the housing, or steam from the engine compartment.

Q: Does this assembly include a new thermostat?
A: Yes, this is a complete kit. It comes with the thermostat pre-installed in the housing, along with a new O-ring seal and clamp for a comprehensive replacement.

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.