Mercury – Quicksilver 815407A2 Distributor Cap Kit | V6 GM MerCruiser Engines | Thunderbolt IV & V HEI Ignition | 815407A2

Overview

When your boat fires up instantly and idles smooth, that’s your ignition system doing its job — and the Quicksilver 815407A2 Distributor Cap Kit helps keep it that way. Built for marinized V6 MerCruiser engines made by GM using Thunderbolt IV and V HEI ignition systems, this OEM cap delivers the clean, steady spark your engine depends on.

It’s made from durable, heat-resistant materials that stand up to marine life — salt spray, vibration, and constant temperature swings. If your engine has been misfiring, idling rough, or showing corrosion around the terminals, this simple replacement will bring your ignition back to factory-fresh reliability.

Key Features

• Purpose: Replaces a worn or corroded distributor cap to maintain accurate spark delivery and timing.
• Fitment: For V6 MerCruiser engines by General Motors equipped with Thunderbolt IV and V HEI ignition systems.
• Construction: Molded from a PBT/PET composite blend for superior stiffness and resistance to heat warping.
• Electrical Contacts: Solid brass inserts ensure excellent conductivity and corrosion resistance in marine conditions.
• Design Benefit: Built to minimize RFI interference, keeping your onboard electronics and radios free from static.

Engine & Boat Compatibility

• GM-based V6 MerCruiser sterndrive and inboard engines
• Thunderbolt IV and V HEI ignition systems
• Common on sport cruisers, bowriders, and performance boats

Performance & Practical Benefits

The 815407A2 cap plays a big role in how your engine starts, idles, and accelerates. Its brass contacts keep the spark path clean and even, preventing misfires or hesitation under load. The tough PBT/PET housing keeps its shape even in a hot, enclosed engine compartment, while the RFI-resistant design helps keep electronic systems — like depth finders and radios — running interference-free.

Replacing a distributor cap might feel like small maintenance, but it restores the sharp spark timing that gives your motor that confident, effortless sound every boater wants to hear.

Why Buy OEM

Mercury builds its ignition components specifically for marine conditions, not automotive ones. Their OEM caps are engineered for resistance to salt corrosion, vibration, and long-term heat exposure. Aftermarket caps might look similar, but small differences in materials or internal tolerances can lead to poor sealing or early failure.

When you use a genuine Quicksilver cap, you’re putting the same part back on your motor that it had when it left the factory — tested, trusted, and built to last. It’s the right fit and the right fix, every time.

FAQ

Q1: What engines fit the Quicksilver 815407A2?
A: It fits V6 GM-based MerCruiser sterndrive and inboard engines with Thunderbolt IV or V HEI ignition systems.

Q2: Does this kit include the rotor?
A: This part includes the distributor cap only — the rotor is sold separately.

Q3: Is it safe for saltwater boats?
A: Yes. The cap’s brass terminals and composite shell resist corrosion and heat in both saltwater and freshwater use.

Q4: Can I install it myself?
A: Definitely. With a few hand tools and basic knowledge, you can replace it in under an hour.

Q5: What are signs my distributor cap needs replacing?
A: Rough idle, hard starting, or visible corrosion or cracks around the terminals are all signs it’s time for a new one.