Compu-Fire Single Fire Ignition Coil, 12V/3 Ohm for Harley-Davidson

3 ohm primary resistor for use with electronic ignition systems.
Supplies up to 50,000 Volts of power.
Note: Difference between Single Fire and Dual Fire: - Dual Fire: This is how pre-Twin Cam engines work.
A single coil is used and both spark plugs fire simultaneously.
This is the simplest system. It's sometimes said that "wasted" spark steals horsepower.
- Single Fire: This is how the original Twin Cam engines from 00 onwards worked.
Two separate coils will fire the spark plugs independently, and only the spark plug of the cylinder that is on the compression stroke will fire.
These engines are said to vibrate less and can improve power.
The effects will be more pronounced with hotter chambers and higher RPMs.

Fits: > 65-99 BT; 65-03XL. For models with Custom Single Fire electronic ignition carburetor (except Twin Cam and other Single Fire applications)