Accel single fire/dual fire ignition module

Works with single and dual fire ignition set-ups. Features 14 advance curves from stock to extreme and an adjustable rev. limiter. VOES imput option and tachometer output. Front cylinder static timing with a L.E.D. light for easy set-up. Note: The difference between single dual fire explained: - 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.