Replace Ultima 53-660 FITS Harley Big Twin 1970-1999 (Except Twin Cam) FITS Sportster 1986-2003 (Except S Models) [Installation] 1. Safety & Removal: Disconnect the battery's negative terminal, then the old distributor cap, rotor, and ignition components. 2. Install New Parts: Mount the new rotor onto the distributor shaft and secure the ignition module. 3. Connect Wires: Plug the distributor harness into the module and connect the coil's wires to it. Reconnect the battery. 4. Final Check: Start the engine and verify the ignition timing with a timing light. Programmable Features: 8 point fully definable wide open throttle curve 8 point fully definable part throttle curve Rev. limit programmable in 50 rpm steps Programmable dead cranking revs 0-10 Programmable rear cylinder offset, total of +/-10° Programmable rev limiter Short circuit protection. Over 30,000 volt coil with fast rise times and high energy. Separate programmable break-in rev limiter.