Quicksilver 805759Q3 Distributor Cap Kit for MerCruiser V8 | Thunderbolt IV & V HEI

Overview

The Quicksilver 805759Q3 Distributor Cap Kit is a marine-grade replacement set designed for Marinized, V8 MerCruiser engines equipped with Thunderbolt IV and V HEI ignition systems. This kit provides a complete refresh for the distributor cap, rotor, and cap gasket, offering a practical upgrade for ongoing maintenance.

Build quality you can feel

The cap is molded from a durable blend of PBT and PET plastics, delivering enhanced strength, stiffness, and resistance to warpage in demanding marine conditions. Solid brass inserts resist corrosion and electrical pitting, helping maintain consistent spark paths and reliable performance. The design also helps minimize RF interference with onboard electronics, supporting smoother instrument readings and engine control signals.

Engine compatibility and fit

Manufactured to Mercury Marine original equipment manufacturer specifications, this kit is intended to protect MerCruiser engines while preserving proper fit and seal. It’s designed for Marinized V8 MerCruiser blocks that rely on Thunderbolt IV or V HEI ignition systems, providing a straightforward path to keep ignition components aligned with factory expectations.

• Comprehensive replacement set: cap, rotor, and cap gasket for a complete service.
• OEM-spec engineering ensures reliable compatibility with MerCruiser and GM-based ignition layouts.

Why consider this kit?

Regularly replacing worn cap and rotor parts can contribute to smoother starts and more consistent timing under load. Brass inserts offer durability against corrosion, and the RF-interference-aware design helps protect sensitive boat electronics. This kit presents a practical option for marine maintenance, focusing on protection, performance, and peace of mind.

• Potential reliability improvements during high-speed or saltwater use.
• Potential longer service life due to corrosion-resistant components.

For replacement guidance, see your owner’s manual. Quicksilver has built its reputation on marine-grade parts and thoughtful engineering, aiming to deliver performance, protection, and peace of mind for engines and power systems in demanding environments.