Mercury – Quicksilver 8M0204653 Prop Lock Nut | Propeller & Drivetrain Hardware | Stainless Steel | 8M0204653

Overview

There’s a certain confidence that settles in when you know your prop is locked down tight the kind of confidence that lets you open the throttle without a second thought. Out on the water, small details like a properly secured propeller make all the difference in how your boat feels and performs. This Mercury Marine part brings back that trust. It’s the kind of hardware you rarely notice, yet you rely on every time the engine pushes your boat forward, whether you’re easing out of the marina or charging across open chop.

Key Features

• Prop lock nut designed to secure the propeller on select Mercury drivetrains
• Made from marine-grade Stainless Steel for maximum strength and corrosion resistance
• Built to meet Mercury M-228-T specifications
• Extreme tensile strength for long-term durability in harsh marine environments
• Manufactured to Mercury Marine part number 8M0204653
• Used on MCM inner transom studs and Mercury thirty-nine and sixty horsepower (1968 and newer, eight-spline) systems

Engine & Boat Compatibility

• Fits Mercury thirty-nine and sixty horsepower outboards with eight-spline prop shafts
• Compatible with MCM inner transom stud applications
• Common on older fishing rigs, aluminum runabouts, and classic recreational setups
• Suitable for both freshwater and saltwater boats that require secure prop fastening

Performance & Practical Benefits

A strong prop lock nut affects more than you might think. When it’s built right, you’ll feel a smoother, more confident handoff of power from the engine to the water. The Stainless Steel construction stays tight and secure, resisting the vibration, torque, and constant movement that occur during long days on the water. Once installed, the nut maintains a firm hold that keeps your prop where it should be — seated tight, spinning true, and transferring every bit of thrust cleanly.

In real use, that means fewer worries and more time enjoying the ride. You’ll notice how steady everything feels when you accelerate, how the engine’s push translates smoothly, and how reassuring it is to know your prop is properly anchored. Installation is simple and familiar, threading on cleanly and tightening with confidence. With its high tensile strength, this nut stands up to repeated stress without deforming or loosening, even after seasons of hard use.

Why Buy OEM

Prop hardware isn’t an area where you want to take shortcuts. A genuine Mercury Marine part ensures the dimensions, material hardness, and threading all match your drivetrain exactly. Aftermarket nuts may look similar, but small inconsistencies can lead to loose fitment, corrosion issues, or premature failure — none of which you want happening miles from shore.

Choosing the correct Mercury Marine part number means choosing reliability. It protects your propeller, your gearbox, and ultimately your day on the water. It’s the kind of smart, practical advice you’d hear from an experienced boater leaning over the dock rail: go with the hardware Mercury built for your engine, and you’ll avoid headaches later.

FAQ

Q1: Which Mercury systems does the Prop Lock Nut 8M0204653 fit?

It fits MCM inner transom studs and Mercury thirty-nine and sixty horsepower, eight-spline systems from 1968 and newer.

Q2: What makes this nut better than aftermarket alternatives?

It’s made from high-strength Stainless Steel, meets Mercury’s M-228-T spec, and provides the precise fit required for secure prop fastening.

Q3: How do I know if this is the correct replacement?

Match your current prop shaft size and spline count, or check your manual for part number 8M0204653.

Q4: Can it be used in both saltwater and freshwater?

Yes — the Stainless Steel construction resists corrosion exceptionally well in both environments.

Q5: Is installation straightforward?

Absolutely. If you’ve ever removed or installed a propeller, this nut threads and tightens easily using common marine tools.

• Supersessions
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