Compu-Fire Single-Fire Ignition System For Harley BT XL Features Easy way to convert stock ignition systems to single-fire system Kits feature Compu-fire ignition module, high-output single-fire coil which mounts in the stock location and under the stock coil cover, and a set of silicone-jacketed spiral-core spark plug wires Ignition modules feature eight pre-programmed advance curves Tunable Voes adds 5 or 10 degrees vacuum advance Easy installation with LED static timing light Selectable rpm limiter from 6,000 rpm to unlimited