53-644 Programmable Ignition Module Compatible with Harley Big Twin 1970-1999 & Sportster 1971-2003 (Except 1200S), Fits S&S Ultima RevTech Carb Engines

Precise Ignition Control: Programmable Single Fire design operates each spark plug independently for stable performance. Adjustable Settings: Multiple selectable advance curves, rev limit options, and single/dual fire modes for flexible setup. Easy Setup: Built-in LED indicator assists with static timing and installation alignment. Durable Construction: Heat-resistant aluminum housing with sealed epoxy design for protection against vibration and moisture. Fitment: For carbureted Compatible with Harley-Davidson Big Twin (1970–1999) and Sportster (1971–2003, except 1200S Sport). Use 2.5–3.5 Ω ignition coils.

• 【Wide Fitment & Compatibility】 Designed to replace OE number 53-644, this programmable ignition module Compatible with Harley Evolution-based engines, including S&S, Ultima, RevTech, and Shovelhead. Suitable for 1970–1999 Carbureted Big Twin and 1971–2003 Sportster (except 1200S Sport) models. Not compatible with EFI systems.
• 【Programmable Single Fire Technology】 Features a Single Fire ignition design that operates each spark plug independently, helping provide stable idling, reliable starts, and responsive performance. Includes multiple selectable advance curves to suit different engine setups and riding preferences.
• 【Easy Installation & LED Timing Setup】 Simple plug-and-play replacement—just disconnect the battery, remove the old module, and wire according to color codes: White → +12V on coil Pink → Rear cylinder Blue → Front cylinder Green → Tach signal (optional) Violet → VOES (optional) Use the built-in LED to set timing accurately—no external timing light required.
• 【Reliable Build & Smart Protection】 Built with a durable aluminum alloy housing and thermally conductive epoxy for excellent vibration, heat, and moisture resistance. Includes intelligent overvoltage, overcurrent, and short-circuit protection plus active dwell control for maximum spark energy and extended coil life.
• 【Professional Performance Tips】 For carbureted engines only. Use 2.5–3.5 Ω ignition coils and carbon or spiral-core plug wires for optimal performance. If the LED indicator flashes rapidly, check coil resistance and wiring. Keep all connectors clean and tight for stable, long-term operation.