Mercury – Quicksilver Blue Wire Spark Plug Wire Kit | V8 High-Performance Ignition System | Marine Grade | 847701Q7

Overview

The Quicksilver 847701Q7 Blue Wire Spark Plug Wire Kit is designed for V8 MerCruiser high-performance engines—including 454, 502, 540, and 572 CID models equipped with Thunderbolt IV ignition systems (1990 and newer). Built by Mercury Marine, this OEM wire set delivers strong, consistent spark even under the toughest conditions. Each wire is factory-cut to exact length and fitted with high-quality boots to ensure a clean, secure connection for maximum performance on the water.

Key Features

• Purpose: Delivers steady, reliable spark to all cylinders for consistent ignition and clean engine performance.
• Material: Made from marine-grade silicone that resists heat, cracking, and corrosion in salt or freshwater.
• Performance: Maintains high spark voltage for crisp acceleration and smooth running at all RPM ranges.
• Design: Pre-measured blue wires with snug-fitting boots tailored to each plug location.
• Ease of Use/Install: Plug-and-play setup—no cutting, trimming, or adjustments needed.

Compatibility

• Engines:
• MerCruiser High-Performance V8s (454, 502, 540, 572 CID)
• With Thunderbolt IV Ignition Systems (1990 & Newer)
• Type: Inboard High-Performance Marine Engines
• Common Boats: Offshore Rigs | Racing Boats | Sport Cruisers | Classic Muscle Inboards

Performance & Real-World Benefits

This Quicksilver wire set gives your big-block V8 the spark it needs to stay responsive and reliable under load. You’ll notice faster starts, steadier idle, and strong, smooth pull across the power band. The marine-grade insulation handles extreme heat and moisture without losing conductivity, keeping your ignition system dependable no matter how hard you run your boat.

Why Choose OEM

With Mercury Marine OEM parts, you’re getting components designed specifically for your engine—not a one-size-fits-all aftermarket substitute. OEM wires are tested for voltage consistency, heat tolerance, and corrosion resistance to handle real marine conditions. Aftermarket sets can fall short on length or insulation quality, which can cause misfires or reduced performance. OEM ensures perfect fit, lasting durability, and peace of mind every time you turn the key.

FAQ

Q1: What engines does this wire kit fit?
It fits V8 MerCruiser high-performance engines (454, 502, 540, and 572 CID) with Thunderbolt IV ignition systems.

Q2: Are these wires pre-cut and ready to install?
Yes, they come factory-cut to length with pre-installed boots for quick, easy setup.

Q3: Can I use them in saltwater conditions?
Absolutely. The marine-grade silicone insulation resists corrosion and moisture damage.

Q4: Will this improve my engine’s performance?
Yes. Consistent spark helps your motor start faster, idle smoother, and run cleaner under load.

Q5: How many wires come in the set?
It’s a full eight-wire kit—one wire for each cylinder.