S&S Cycle HI-4N Single & Dual Fire Ignition Module For Harley 1984-1999

Versatile Ignition Modes: Single or Dual Fire

The HI-4N is designed for maximum flexibility. With a simple flip of a switch, you can configure the module for Dual-Fire (using your stock coil) or Single-Fire (firing each cylinder independently for smoother operation and reduced vibration). This makes it an ideal choice for riders who want to upgrade their ignition module now and potentially move to a high-output single-fire coil system later without buying a new ignition.

Optimized Performance Tuning

Tuning your V-Twin has never been easier. The HI-4N features on-board rotary switches that allow you to select from four different advance curves, ranging from stock to aggressive performance maps. This allows you to eliminate engine “pinging” (detonation) while maximizing torque. Additionally, the module features a separate rear cylinder timing adjustment, allowing you to offset the timing of the rear cylinder to ensure it runs cooler and more efficiently than the front.

Selectable Start Modes: Electric or Kick

Whether you are riding a modern electric-start Softail or a custom kick-only chopper, the HI-4N has you covered. The “Kick Start” mode provides a spark on the very first compression stroke for immediate ignition. The “Electric Start” mode delays the spark for two revolutions, allowing the starter motor to reach full speed—this virtually eliminates engine kick-back, protecting your starter and ring gear from expensive damage.

Rugged Construction & Built-in Protection

The HI-4N is built to survive. The electronics are fully encapsulated (potted) to protect against moisture, oil, and mechanical shock. It includes a built-in adjustable rev limiter that can be set in 100-RPM increments to protect your valvetrain. A built-in static timing LED allows you to time the engine perfectly without the need for a strobe light, making installation straightforward for the DIY mechanic.

Fitment and Compatibility (1984–1999)

This module (Part # 550-0501) fits “nose cone” ignition applications:

• Harley Big Twin (1984–1999): Evolution (Evo) engines (Softail, Dyna, and Touring).
• Harley Sportster (1986–2003): All 883 and 1200 Evolution Sportster models.
• Custom V-Twins: Direct replacement for S&S V-Series and other aftermarket Evo-style engines.