200405 2004 Ignition Upgrade . doc     Page 1 of 1 · mounts directly in place of the original equipment ignition module for a simple installation · integrated high - output single fire operation for outstanding engine performance · fully programmable spark timing and rev - limit via the included Smart Link software makes tuning limitless! · adjustable dwell to take full advantage of   performance coils · real - time diagnostic features aid in troubleshooting and tuning · improved starting and performance · rugged billet aluminum housing is weather and vibration - proof for years of trouble - free service · programmable nitrous oxide activation output · programmable shift light activation output · tachometer output allows the use of an aftermarket tach   · programmable auxiliary “stage” rev limiter · includes software, communication cable, module, and comprehensive instructions Looking to add some zap to your 2004 Harley? Look no further than Thunder Heart’s 2004 Ignition Upgrade Module! The ASM5075 bolts directly in place of the factory ignition module . The included Smart Link software allows the user to fully program the front and rear spark timing and rev limit . In addition, the ASM5075 has four additional outputs to control nitrous oxide activation, a “stage” rev limiter, a shift light, and a tachometer output for use with most aftermarket tachs! Carbureted 2004 Harley Davidsons (including Sportster)