Mercury – Quicksilver Distributor Cap Kit | For GM V8 MerCruiser Engines with Thunderbolt IV & V Systems | 805759T1

Overview

When your engine starts hesitating, missing, or losing power, it’s often the distributor cap showing its age. The Mercury Marine 805759T1 Quicksilver Distributor Cap Kit brings back the clean, consistent spark your V8 MerCruiser needs. Designed for marinized GM-built engines running Thunderbolt IV and V HEI ignition systems, this cap is built tough — molded from high-strength composite material and fitted with solid brass terminals that stay clean and resist corrosion. It’s made to take the heat, the vibration, and the salt so your boat keeps firing perfectly every time you hit the water.

Key Features

• Purpose: Restores proper spark timing and power delivery across all cylinders.
• Build: Made from a PBT/PET composite that won’t warp, crack, or break under marine heat.
• Contacts: Uses solid brass terminals for superior conductivity and long life.
• Protection: Reduces electrical interference with onboard electronics.
• Longevity: Designed to handle real marine stress — heat, moisture, and constant vibration.

Engine & Boat Compatibility

• GM-based V8 MerCruiser sterndrive and inboard engines
• Works with Thunderbolt IV and Thunderbolt V HEI ignition systems

Performance & Real-World Benefits

The 805759T1 cap helps your ignition system do its job right — delivering a strong, even spark to every cylinder. As caps age, they can collect moisture, build up corrosion, or develop small cracks that weaken performance. Replacing it with this Mercury OEM cap restores consistent ignition and reliable starts.

Its high-strength housing stands up to the extreme heat inside your engine compartment, while the brass terminals ensure a clean electrical path. The result? Faster starts, smoother idle, and stronger throttle response — whether you’re cruising or towing.

And because it’s built for marine use, it holds up in ways automotive caps simply can’t.

Why Choose Mercury OEM

The Quicksilver 805759T1 is built by Mercury for Mercury — the same part used in new MerCruiser engines. Aftermarket copies might look similar, but they often use softer plastics or cheaper metals that can corrode and fail early.

Mercury’s OEM components are tested under real-world marine conditions for strength, heat resistance, and precise fit. You’re not just replacing a part — you’re restoring your engine to factory performance and reliability.

FAQ

Q1: What engines is this designed for?
It fits GM-built V8 MerCruiser engines with Thunderbolt IV or V HEI ignition systems.

Q2: What’s included in the kit?
The distributor cap only (rotor sold separately).

Q3: Why brass terminals?
Because brass doesn’t corrode easily and delivers a steady, strong spark.

Q4: Can I install it myself?
Yes — it’s a direct-fit OEM replacement that installs with basic tools.

Q5: Why use Mercury OEM parts?
Because OEM means precision, durability, and reliability, built for real marine conditions.