Single fire coil. For dual plugged head (4 spark plugs total) in single fire applications. 3 ohm primary resistance. Compatible with Dyna 2000i and most other electronic ignition systems. Note: Not compatible with Dyna-S ignition modules, which require 5 ohm primary resistance. Note: It is recommended to use ignition modules & coils of the same manufacturer. Intermixing different brands may cause premature failure. Note: Difference between Single & Dual Fire: – Dual Fire – This is the way the earlier, pre-Twin Cam, engines work. A single coil is used and both spark plugs fire simultaneously. This is the simplest system. The ‘wasted’ spark is sometimes said to be horsepower robbing. – Single Fire – This is the way the stock 00-up Twin Cam engines work. Two separate coils will fire the spark plugs independently and only the spark plug of the cylinder that is on compression stroke will be fired. It is said that these engines vibrate less and can improve power. The effects will become more pronounced with hotter cams and higher RPM.
Dynatek, Twin Fire coil. Single fire, 4 plug