Old Britts – Power Arc Advanced Electronic Ignition for Commandos
Download the complete PDF version using the green download button at the top right of this page for an Old Britts technical guide covering the original Power Arc Advanced Electronic Ignition system for Norton Commandos. This article explains the features, installation process, wiring requirements, ignition timing setup and operating characteristics of the Power Arc electronic ignition system developed as an alternative to the long-running Boyer setup.
The guide begins by outlining the major features of the ignition including low-voltage operation down to 6 volts, triple-spark firing during each compression stroke, programmable ignition maps, built-in rev limiter, electronic tachometer output and dual selectable advance curves. Old Britts also explains how their ignition maps were developed using engine dyno testing and race testing on Norton Commandos.
Step-by-step installation instructions then cover replacing the original ignition components, mounting the ignition module inside the points compartment, wiring the coil connections for both positive and negative ground systems and configuring the selectable advance curves. Detailed diagrams show the correct wiring layouts and explain precautions regarding resistor spark plug wires and spark plug gaps.
The final sections explain installation of the optical encoder disc, finding top dead center, static timing adjustment using the built-in LED indicator and the recommended kick-start sequence to avoid ignition kickback. The article also includes warranty information and several close-up installation photos and diagrams.
Contents Include
- Power Arc Advanced Electronic Ignition overview
- Features and operating characteristics
- Dual ignition maps and programmable advance curves
- Low-voltage operation for electric start Commandos
- Triple-spark firing system explanation
- Positive and negative ground wiring diagrams
- Coil wiring and ignition module installation
- Resistor spark plug wire recommendations
- Spark plug gap setup information
- Encoder disc assembly and installation
- Static timing using the built-in LED indicator
- Top dead center setup procedures
- Recommended starting sequence to prevent kickback
- Dyno testing and race testing notes
- Warranty and service information
