Mercury – FourStroke 300 Hour Maintenance Kit | 4–6hp Service Package | Precision Components | 8M0120836

Overview

If you run a small outboard, you know exactly how much it carries on its shoulders. These little engines are the ones pushing dinghies through quiet coves, powering small fishing boats toward early-morning bites, and helping families explore the shoreline one slow drift at a time. They may be compact, but when you depend on them, you depend on them completely. And there is a certain comfort in knowing that your engine is serviced with the right parts—no guesswork, no second-best substitutes, just pure reliability.

The Mercury 8M0120836 300 Hour Maintenance Kit is designed for boaters who want that feeling every time they squeeze the primer bulb or pull the starter. It gathers the exact components your 4–6 horsepower FourStroke outboard needs at its 300-hour mark, all in one neat, ready-to-go package. With this kit, you’re not just doing scheduled maintenance—you’re preserving the smooth, steady performance that keeps your days on the water easy and enjoyable.

Key Features

• Complete Mercury 300-hour service kit for 4–6 horsepower FourStroke outboards
• Includes fuel filter, oil drain seal, gearcase seals, thermostat and thermostat gaskets
• Comes with spark plug, water pump impeller kit, and unit anode
• High-pleat fuel and oil filters deliver strong filtration and clean operation
• Heavy-duty electroplated housings designed to resist corrosion
• Engineered to Mercury Marine standards for perfect fit and dependable performance

Engine & Boat Compatibility

• Designed for Mercury 4 horsepower, 5 horsepower, and 6 horsepower FourStroke outboards
• Ideal for dinghies, sailboat auxiliaries, jon boats, tenders, small inflatables, compact skiffs, and lightweight fishing boats
• Works with tiller and remote-steer configurations

Performance & Practical Benefits

A small FourStroke engine can run beautifully for years, but only if its cooling system, fuel system, and lower unit are cared for. This kit makes that simple. The impeller and seals restore cooling flow so the engine runs at a stable temperature, even on hot summer days. The filters keep fuel clean and steady, reducing sputtering or mid-throttle hesitation. The thermostat and spark plug help the motor start easily, warm properly, and stay smooth under load.

Everything in this kit is designed to fit tightly and install cleanly. You will feel the difference after service—crisper throttle response, cooler running temperatures, and the satisfying sense that the engine is working with you, not against you. It is the kind of maintenance that eliminates surprises and gives you confidence on every tide change and every shoreline run.

Why Buy OEM

• Guaranteed Mercury Marine quality and compatibility
• Protects engine longevity and reduces long-term repair costs
• Ensures proper cooling, filtration, and ignition performance
• More dependable than aftermarket kits that may not meet Mercury specifications
• Helps maintain warranty compliance and resale value

Think of it as taking care of the heart of your boat the right way—once, correctly, and with parts you know will last.

FAQ

Q1: Which engines does the 8M0120836 kit fit?

It fits Mercury 4–6 horsepower FourStroke outboards.

Q2: What makes this better than aftermarket kits?

OEM parts match exact Mercury tolerances, materials, and engineering, which means better protection and more consistent performance.

Q3: How do I confirm this is the correct kit?

Match your engine model and horsepower to the compatibility listed here or check your owner’s manual.

Q4: Can it be used in saltwater and freshwater?

Absolutely—these parts are built for harsh marine use in any environment.

Q5: Is the installation manageable for most boaters?

Yes. If you’re comfortable completing standard outboard maintenance, this kit is straightforward and clean to install.