Mercury – Black Max High Thrust Propeller | 8.4" Diameter x 6" Pitch | Right-Hand Rotation | 3 Blades | Aluminum | Glossy Phantom Black Finish | 812951A02

Overview

There’s a certain comfort in knowing your boat will respond exactly how you want it to — steady, predictable, and smooth. The Mercury Black Max 3-Blade High Thrust Aluminum Propeller is made for that kind of confidence. It is designed for smaller Mercury outboards, it gives you the extra push and steering authority you need when precision matters most. Whether you’re guiding through a tight marina or cruising calm water at low speed, this prop makes it all feel effortless and in control.

Key Features

• Diameter and Pitch: 8.4" Diameter x 6" Pitch
• Rotation: Right-Hand
• Blade Count: 3 Blades
• Material: Mercury’s Patented Mercalloy Aluminum Alloy for strength and flexibility
• Finish: Glossy Phantom Black Enamel for long-lasting shine and corrosion resistance
• Hub System: Rubber bushing helps absorb vibration and protect drivetrain components
• Design Details: High-thrust blade design with larger surface area for improved lift and handling control

Engine & Boat Compatibility

• Fits Mercury and Mariner 4–6hp FourStroke (1999 and newer) outboards
• Compatible with 4–5hp TwoStroke (1987 and newer) outboards
• Ideal for small fishing boats, dinghies, inflatables, and lightweight utility boats
• Perfect for trolling, slow cruising, and situations where tight maneuvering and precise control are key

Performance Benefits

• You’ll feel the difference as soon as you drop it into gear. The Black Max grips the water with confidence, moving your boat forward with clean, steady thrust that feels natural and controlled. The high-thrust blade design gives you better grip and steering response at low speeds, so your boat reacts smoothly — not abruptly — when you shift or turn. It’s that kind of control that takes the stress out of docking, trolling, or navigating narrow waterways.

• Acceleration feels crisp and balanced, giving your boat a smooth, confident lift without strain. Once you’re cruising, it holds a steady rhythm — no slipping, no chatter — just consistent performance that feels effortless. The larger blade surface helps your motor work efficiently, making it easier to maintain speed without over-revving, which means quieter runs and better fuel economy.

• Durability is built into every inch. The Mercalloy aluminum construction blends strength with a touch of flexibility, allowing it to withstand small bumps from sandbars, rocks, or debris without losing its shape. The rubber hub absorbs vibration and cushions your drivetrain from sudden impacts, extending both comfort and longevity. Maintenance is simple too — a quick rinse after use and it’s ready for the next trip.

• The Phantom Black enamel finish not only gives it a sharp, polished look but also defends against corrosion in both saltwater and freshwater. It’s a prop designed for boaters who want reliability they can count on, season after season.

Why is this prop is a strong choice vs. alternatives?

• Mercury OEM Quality: Engineered by Mercury for precision fit, strength, and dependable performance.
• Reliable and Easy to Maintain: Durable Mercalloy construction with simple, low-stress upkeep.
• Cost-Effective Choice: Delivers excellent thrust and protection at a lower cost than stainless steel.
• Versatile Fit: Performs beautifully across multiple small outboards and boat types.
• Proven Dependability: Trusted by boaters for its smooth handling, steady thrust, and quiet operation.

FAQ

• Q1: Which Mercury engines does the Black Max High Thrust 3-Blade Aluminum Propeller fit?
It fits Mercury and Mariner 4–6hp FourStroke (1999 and newer) and 4–5hp TwoStroke (1987 and newer) outboards.

• Q2: What makes this propeller different from other Mercury options?
Its high-thrust blade design offers improved steering authority and smoother control at lower speeds, making it ideal for trolling, maneuvering, and tight navigation.

• Q3: How do I know if this pitch or size is right for my boat?
If you’re using a 4–6 horsepower Mercury outboard and want stronger lift, better grip, and easier control at slow speeds, the 8.4" x 6" pitch is a great fit. You can confirm with your owner’s manual or local dealer.

• Q4: Can this prop be used in both saltwater and freshwater?
Yes, the Phantom Black enamel finish protects against corrosion in both environments, keeping your prop looking sharp and performing reliably.

• Q5: What hub system does it use?
It features a rubber bushing hub that absorbs vibration and cushions your drivetrain from minor impacts for a smoother, quieter ride.