S&S HI-4N Ignition

The S&S HI-4N ignition system for Harley-Davidson engines combines a compact design with extensive features for vintage and modernized Big Twins. With four step switches, operating mode, ignition curve, and rev limiter (1,500–9,900 RPM) can be precisely adjusted – ideal for Big Twin models (1970–1999) and Sportster models (1971–1990).

Available operating modes:

• Single Fire
• Dual Fire
• OEM Ignition Curve
• Racing Ignition Curve
• Kickstart
• Electric Start

The robust aluminum housing reliably protects the electronics from vibration, moisture, and dirt while supporting heat dissipation. Degree markings on the flange make fine adjustment of the ignition timing easier, while a cable slot simplifies installation.

Easy installation and durability:

The mounts for the sensors and magnets are directly integrated into the housing, ensuring that the high-quality samarium-cobalt magnets remain optimally protected during assembly. Additionally, flux concentrators strengthen the magnetic field, guaranteeing precise and reliable switching of the Hall sensors.

Notes for road use:

For optimal performance, S&S recommends ignition coils with at least 2 Ω. Coils above 4 Ω may impair system performance.