Compu-Fire, ignition module. Electronic advance

For electric start models only. Same as 538404 but with slower advance curves for high compression engines that struggle with detonation issues. Full advance is reached at a higher RPM. Comes with selectable single/dual fire and/or single/dual plug. Selectable advance & RPM limiter. With 8 advance curves and 8 RPM limits, from 6000 up to 7500 RPM, it can be adjusted to fit your specific engine. Easy selection by a rotary switch on the ignition unit. All modules come with a built-in static timing light and feature a extended temperature and low voltage operation with soft-start circuitry for easy starting. Note: A tach adapter (MCS 538408) is required to correct tacho-output when using single fire ignition, for correct RPM representation.

Fits: > 70-99 Big Twin (excl. Twin Cam, excl. injection models); 71-01 Sportster (excl. 1200S) (NU)