Mercury – SpitFire X7 4-Blade Stainless Steel Propeller | 12.8" Diameter x 19" Pitch | Right-Hand Rotation | 4-Blade | Stainless Steel | Polished Finish | 8M0151363

Overview

If you’ve ever felt that perfect mix of power and precision when your boat hooks up and takes off, you’ll understand why the Mercury SpitFire X7 12.8x19 Right-Hand 4-Blade Stainless Steel Propeller (8M0151363) has such a loyal following. It’s built for boaters who live for that instant throttle response the kind that sends your boat out of the hole and onto plane before you can even grin.

This prop doesn’t just deliver speed; it delivers control. It’s the bridge between raw horsepower and pure confidence, turning every turn, trim, and throttle adjustment into something you can feel. Whether you’re carving through open water or cruising smooth and steady, the SpitFire X7 keeps your boat locked in, responsive, and eager for more.

Key Features

• Diameter and Pitch: 12.8" Diameter x 19" Pitch
• Rotation: Right-Hand Rotation
• Blade Count: 4-Blade Design
• Material: Mercury X7 Stainless Steel Alloy (30% stronger and four times more durable than standard stainless steel)
• Finish: Polished Stainless Steel
• Hub System: Requires a Mercury hub kit (sold separately)
• Design Details: Aggressive blade geometry for top-end speed, rapid acceleration, and firm handling; Performance Vent System (PVS) for customizable hole shot tuning

Engine & Boat Compatibility

• Works with Mercury and Mariner 40–60 HP Command Thrust Outboards (4.25-inch gearcase)
• Fits Mercury 75–125 HP TwoStroke and FourStroke Outboards
• Great match for midsize boats, fishing boats, and performance runabouts
• Suitable for freshwater and saltwater use

Performance Benefits

The SpitFire X7 12.8x19 is for boaters who want it all—speed, grip, and finesse in one compact design. Its smaller diameter and aggressive four-blade setup bite hard, lifting your boat quickly onto plane with minimal bow rise. You’ll feel the acceleration instantly, a clean and powerful launch that transitions seamlessly into a steady, confident cruise. The prop grips tight even in sharp turns, maintaining lift and control whether you’re solo or fully loaded with gear.

What makes it even more impressive is how it maintains balance and smoothness at high speeds. The X7 stainless steel alloy resists flexing under heavy torque, meaning your performance stays consistent no matter how hard you push it. And with the built-in Performance Vent System, you can customize your hole shot by adjusting exhaust venting—tuning your acceleration exactly to your liking. It’s the difference between “almost perfect” and “just right.”

Why is this prop a strong choice vs. alternatives?

• Mercury OEM Precision: Designed and tested by Mercury engineers for exact fit, durability, and balanced performance.
• Fast and Forgiving: Four-blade geometry offers explosive acceleration with steady handling and superior grip in turns.
• Unmatched Strength: X7 stainless steel is 30% stronger and four times more durable than standard stainless props.
• Tunable Performance: PVS allows you to adjust acceleration and hole shot for your specific setup and conditions.
• Versatile Application: Ideal for midsize boats and outboards, offering dependable performance across water types and activities.

FAQ Section

Q1: Which Mercury engines does the SpitFire X7 fit?

It fits Mercury and Mariner 40–60 HP Command Thrust outboards with the 4.25-inch gearcase, as well as Mercury 75–125 HP TwoStroke and FourStroke outboards.

Q2: What makes this propeller different from other Mercury options?

The SpitFire X7 uses Mercury’s X7 stainless steel alloy and aggressive four-blade geometry, giving it exceptional acceleration, top-end speed, and high durability compared to other stainless props.

Q3: How do I know if this pitch or size is right for my boat?

If your engine revs near the top of its recommended RPM range or you want more lift and better control at high speeds, the 19-pitch SpitFire X7 is a strong match.

Q4: Can this prop be used in both saltwater and freshwater?

Absolutely. The stainless steel construction and polished finish resist corrosion, ensuring excellent performance in any environment.

Q5: What hub system does it use?

It requires a Mercury hub kit (sold separately) for a secure fit, quiet operation, and smooth performance.