S&S Cycle Ignition System For All 1999–03 Carbureted Harley-Davidson Twin Cam 88 Engines User Manual

Page 3

All Harley-Davidson® Twin Cam 88® motorcycles for this ignition application came from the factory with a single fire ignition. The stock coil has
a small 3-connector plug. If a Twin Cam 88® motorcycle is equipped with the OEM coil, there is no need to change it. If the bike was previously
customized, the ignition may have been changed. Verify coil type per below.

Ignition Coil Identification

Dual Fire Coil

In addition to the spark plug terminals, an aftermarket dual fire coil will have two wiring terminals: positive, negative.

Single Fire Coil

In addition to the spark plug terminals, an aftermarket single fire coil will have three wiring terminals: A negative terminal for the front cylinder,
a common 12v + terminal, and negative terminal for the rear cylinder, this is the most common type of single fire coil.

All single fire coils are compatible with the S&S® ignition if they have a resistance of .5 to 3 ohms. Coils with higher resistance will decrease
ignition output.

The S&S Ignition system will also support a variety of different ignition coil combinations as long as they are connected for single fire operation,
and yield a final resistance of .5 to 3 ohms. The ignition is also compatible with dual plug heads with the correct coil configuration.

Examples of custom coil/spark plug combinations supported by the S&S ignition:

• One coil single fire for single plug heads

• One coil single fire for dual plug heads.

• Two coil single fire for single plug heads.

• Two coil single fire for dual plug heads.

Spark Plugs and Plug Wires

Spark plugs must be resistor spark plugs (suppression type) of the correct style and heat range for the application. Do not use non-resistor
plugs

Spark plug wires must be suppression type. Do not use solid metal core plug wires.

B. Parts List

The S&S Ignition Installation Kit for 1999–2003 Harley-Davidson® Twin Cam 88® (S&S #55-1012 See Picture 1, below left) is intended only for
installation of S&S Intelligent Spark Technology (IST) Ignition Module. See Picture 2, below right.

S&S Ignition System Installation Kit #55-1012 contains the following items (See Picture 1):

• S&S #55-1017 Wiring Harness Adapter. Items (a) thru (e)

• S&S #55-1014 (H-D® #32446-99) Cylinder Head Temperature Sensor. Item (f)

• S&S #55-1015 Knock Sensor Kit. Items (g) thru (n)

• Loctite® & Wire Ties. Items (o) and (p)

All reference to Harley-Davidson® part numbers is for identification purposes only. We in no way are implying that any of S&S® Cycle’s products are original
equipment parts or that they are equivalent to the corresponding Harley-Davidson® part number shown

Picture 1

Picture 2

S&S® Intelligent Spark Technology ECU Module