Mercury – Quicksilver 8M0177107 Thermostat Gasket | 9.9–60hp Outboard Series | Composite Seal | 8M0177107

Overview

If you’ve spent enough early mornings easing away from the dock, you know how much trust goes into every small part of your engine. Something as simple as a thermostat gasket plays a quiet but essential role in keeping things running smooth and steady. When the water’s cold, the sun’s not up yet, and you’re headed to your favorite spot, you want to know your outboard will warm up the way it should — no leaks, no surprises. The Mercury 8M0177107 Thermostat Gasket helps deliver that peace of mind, sealing your cooling system so your engine stays at the temperature it was designed to run.

Key Features

• Thermostat gasket designed for precision sealing within the cooling system.
• Built from durable composite material engineered for heat and pressure stability.
• Manufactured to Mercury Marine’s exact equipment standards.
• Helps maintain consistent engine temperature and proper thermostat function.
• Designed for select Mercury 9.9–60hp outboards.

Engine & Boat Compatibility

This Mercury Marine part is compatible with:

• Mercury 9.9hp, 15hp, 20hp, 25hp, 30hp, 40hp, 50hp, and 60hp outboard engines (select models only)

Commonly used on:

• Small fishing boats
• Skiffs
• Aluminum jon boats
• Pontoon boats
• Lightweight runabouts and tenders

Performance & Practical Benefits

A strong, reliable thermostat gasket does more than keep water in the right place — it protects the whole temperature-control process. With this Mercury Marine part installed, you’ll notice your outboard warming evenly, holding temperature better, and running smoother during long idle periods or slow trolling passes. The gasket seats cleanly, creating a tight, confident seal that doesn’t compress unevenly or crack under repeated heat cycles.

This stability matters. Your outboard’s cooling system is constantly battling variations in water temperature, load, and operating speed. A dependable seal helps prevent leaks that can cause overheating, reduced performance, or corrosion over time. With the 8M0177107 gasket in place, you get a steady, predictable feel from your motor — exactly what you want when you’re miles from the ramp.

Installation is straightforward for most boat owners comfortable with routine maintenance. Once the mating surfaces are clean, the new gasket drops into position without fuss, restoring that crisp, factory-tight fit.

Why Buy OEM

Experienced boaters know that a gasket isn’t the kind of part where you want to gamble. Aftermarket versions may look similar, but they often fall short on material quality or thickness tolerances. An imperfect seal can cause problems that become expensive fast.

Choosing an OEM Mercury Marine part means:

• Guaranteed fit and compatibility with your exact outboard model
• Materials engineered to withstand marine heat cycles and vibration
• Longer service life compared to generic alternatives
• No guesswork — it works the first time, the way the engine engineers intended
• Better protection for your investment

With OEM components, you’re not just replacing a gasket. You’re protecting the performance and longevity of your outboard.

FAQ

Q1: Which engines does this thermostat gasket fit?

It fits select Mercury 9.9–60hp outboard models. Confirm with your owner’s manual for exact compatibility.

Q2: What makes this gasket different from aftermarket options?

OEM Mercury gaskets are built to strict specifications, ensuring proper sealing, temperature resilience, and long-term durability.

Q3: How can I confirm this is the right replacement?

Match your engine model and year with Mercury’s parts guide or check your service manual.

Q4: Is it suitable for saltwater and freshwater use?

Yes. The material is designed for full marine environments, regardless of water type.

Q5: Is installation simple?

Most boaters comfortable with basic service can install it using standard hand tools.