Dynatek, Dyna-S Single Fire Ignition Module for Harley-Davidson

Dyna-S ignition module for single fire applications.
Comes complete with rotor.
Can be used for single or double connection heads.
The required mechanical feed unit must be purchased separately.
Note: Dyna coil recommendations: Dyna 5 Ohm for street use, Dyna 3 Ohm for race use.
Note: It is recommended to use ignition modules and coils from the same manufacturer.
Mixing different brands can cause premature failure.
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.
Note: For the Dual Fire Dyna-S ignition module, see 902525.

Fits: > 70-99 Big Twin (excl. TC) and 71-03 XL Sportster