The Mercury Racing Switch Box Mercury (OEM Part 332-7778 A14) represents a critical component in maintaining and optimizing the ignition system of Mercury’s legacy 2-stroke V6 outboard engines. Engineered for compatibility with a broad range of models spanning from 1976 to 1999, this switch box supports 2.0L, 2.4L, and 2.5L configurations, including both recreational and high-performance marine applications.
 
Compatibility and Application Range
 
This latest version of the 332-7778 A14 switch box is specifically designed to integrate seamlessly with Mercury V6 2-stroke outboard engines across three decades of production. Whether used in offshore race hulls or freshwater fishing platforms, this component ensures reliable ignition control across various RPM ranges and load conditions.
 
It is compatible with all standard and high-output V6 2-stroke models, making it an ideal replacement for aging or failing ignition systems on engines such as the Mercury XR2, XR4, XR6, and other carbureted or EFI 2-stroke V6 variants.
 
Technical Function and Design
 
The switch box serves as the control interface between the stator and the ignition coils, regulating the precise timing and delivery of electrical energy to the spark plugs. The OEM Race 332-7778 A14 variant features updated internal circuitry for improved durability and timing consistency, especially under high thermal and vibrational stresses typical in marine environments.
 
It maintains signal integrity even under conditions of high engine load or extended wide-open-throttle operation—key for performance-oriented or tournament applications.
 
This updated design ensures optimal dwell and firing voltage across all six cylinders, contributing to cleaner combustion, improved fuel atomization, and minimized misfire under transient acceleration or deceleration. Proper installation restores OE-spec ignition behavior and supports factory timing curves without modification.
 
Cross-Reference and Replacement Guide
 
The OEM Race 332-7778 A14 Mercury Racing Switch Box offers a dependable, specification-matched solution for restoring ignition reliability in 1976–1999 V6 2-stroke Mercury outboards.
 
Its compatibility with a wide range of models, combined with its enhanced internal components, ensures long-term reliability in both recreational and performance marine applications.
 
For technicians and marine mechanics working on legacy Mercury V6 platforms, this switch box was found on the SST-120, 245 HP Carb, 2.5 Liter ROS, 260 EFI, 300 Drag, S3000, and retro-fits back to the SST-140,  2.4 Bridgport, Mod VP, and Champ 2.0 Liter, and remains an essential part for maintaining engine performance and operational safety.
 
The 332-7778 A14 switch box is a direct-fit replacement for a range of earlier OEM and aftermarket part numbers. It supersedes legacy Mercury part numbers such as 114-7778, F749301, F7778A9, 18-5775, 5524-A1, as well as earlier suffix revisions including 7778-A1, 7778-A3, 7778-A6, 7778-A7, 7778-A12, and 7778-A13. This makes it a reliable retrofit option for both single and dual-switch box systems, depending on engine configuration.
 
Includes a set of two (2) Mercury / Quicksilver OEM A14 Switchboxes.
 
For technical support, contact Mike Hill at +1-714-697-1716 or mike@buckshotracing77.com