Instructions - videos

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Concept & Technology Overview


1969 - 1978 Components


1969 - 1978 Control Unit Mounting


1969 - 1978 Installation Instructions 1/2


1969 - 1978 Installation Instructions 2/2


1979 - 1980 Components


1981 - 1984 Control Unit Mounting


1981 - 1996 Components

1981 - 1996 Installation Instructions 1/2


1981 - 1996 Installation Instructions 2/2


Instructions - text


NOTE: The Wedgetail Module does NOT need heat sink paste. Drilling out the rivets and installing heat sink paste will void the warranty. The Wedgetail Module is permanently riveted and sealed to the aluminum heat sink. Please do not try to detach and re-attach the module from the heat sink for any reason.

1) Installation of the WEDGETAIL ignition system is simple. All components are plug- and-play replacements of the OEM parts, with the addition of the ICU module mounts for the 1969-1978 model Airheads, where the module uses the included brackets to mount on the bottom of the fuel tank’s mounting rubbers, on the bottom side of the frame.


Install the module with the wiring connector facing forward between the ignition coils and the label facing DOWN toward the engine case. (See #7 HINT below) Connect all wires exactly as they were on the OEM setup. For 1979 and later models, the ICU module uses the original mounting bolts.


In some of the later bikes, the ICU module is mounted directly to the frame. Your new ICU module can only be mounted via the enclosed bracket. NOTE 1: if the bracket is installed upside-down, the ICU module will interfere with other components. Make sure the bracket is installed so that the front end (the end closer to the coil) is farther from the frame than the rear end (the end closer to the voltage regulator). NOTE 2: The bracket studs should pass through the heat sink AND the module. Do not use the holes located in the upper part of the heat sink to secure the ICU module to the bracket.

The holes in the heatsink may be used to mount the heatsink AND module to the OEM location on the top of the brake line splitter on 81-84 models.Do not drill out the rivets holding the ICU module to the heat sink. This is a permanent connect. No heat sink paste is needed.


Secure the module/heat sink with minimal torque so there is no bending of the module.


2) Use your existing coils (anything from 0.7 to 3.0 ohms impedance is fine, because the WEDGETAIL module has internal protection designed to accommodate your coil choices. If you are using OEM BMW 6 Volt coils, continue to use them as wired (in series.)


3) On 1969 to 1978 models which originally had points and a mechanical advance unit, remove the advance unit, points plate, and condenser. Install the WEDGETAIL timing plate in place of the removed points plate. Reuse the plate hardware (screws and wire retainer clip) and use the retainer clip to hold the wire by the UPPER screw. For initial setup, center the retaining screws in the plate slots and lightly seat the screws with washers.


4) Install the trigger cup onto the camshaft, with the nut and washer just seated, not tight. Using one hand, rotate the cup counterclockwise until it stops against the D-shaped camshaft nose stop, then tighten the lock nut GENTLY. Use this technique any time you remove the timing cup, and you will have consistent timing location.


5) On 1979 and later Airheads with the “bean can" timing device, remove the existing bean can and install the WEDGETAIL trigger unit (bean can) to the engine, observing that the offset drive lugs only can engage ONE WAY to the camshaft grooves. Make sure that you can fully seat the unit to the timing case by hand, NOT using the bolts to pull it in.


6) To set the critical reference timing setting, install all components, remove spark plugs, insert plugs into caps and ground the plugs to the cylinder fins (this is very important EVERY time the ignition switch is ON with the plug wires detached!) Then, using an M6 Allen wrench or socket on the alternator rotor bolt, rotate the crankshaft CLOCKWISE AS VIEWED FROM THE FRONT, while simultaneously observing the TRIGGER lamp and the flywheel timing marks. The Trigger lamp should illuminate AS THE S MARK LINES UP WITH THE NOTCH IN THE CRANKCASE WINDOW, viewed straight on.
This initial timing setting is the REFERENCE for the module software to make all programmed timing changes based on RPM.


It is NOT POSSIBLE to use a strobe timing light for this setting, that is why there is a TRIGGER LED lamp on the module.


7) Hint: if your module is mounted facing down (as on twin coil applications) a piece of shiny foil can be laid below the module and curved so that the LED lamp reflection is easily visible while turning the crankshaft.


8) Set the ignition timing using the LED lamp on the module. The bolts securing the ignition TRIGGER (bean can) should be tight enough to offer some resistance, but you should still be able to rotate it.
Begin with the bolts approximately in the middle of their slots. After installation, reconnect the battery, with the tank off the bike, with the ignition switch ON, and the RUN switch to RUN. Next, rotate the engine manually (not using the starter motor) in clockwise direction as viewed from the front. Continue rotating as necessary to line up the mark beside the "S" (STATIC TIMING) on the flywheel with the notch in the crankcase in the timing window (left side of the crankcase).
Look at the LED lamp as you rotate the crankshaft (a mirror may be useful here). Adjust the ignition module (bean can) until the trigger LED on the ICU module lights just as the "S" mark passes the notch. At this point you have it timed correctly. Tighten the bolts securing the ignition module (bean can) to the front of the engine.
The internal advance timing is all handled inside the module based on engine RPM and a very sophisticated map. Please DO NOT try to defeat this map by different settings.


9) If you want to verify your setting, or simply look at the timing curve at various RPM, use a standard timing light in the normal fashion. You will see that the ignition curve advances smoothly, reflecting the multi-point sampling design of the WEDGETAIL microprocessor. For standard BMW single-plug ignition, you should see your S mark in the window at approximately 1000 RPM, and the F mark will appear at about 3500 RPM. Again, please do not try to adjust those ignition points by readjusting the timing setting of the trigger. If you feel that your module is not giving correct advance, contact us for replacement under the no-questions two-year warranty.


10) If you have the dual-channel ICU module with a slider switch, be sure to check that BOTH circuits are working by checking the timing setting for each switch position. The two circuits are identical. If you have purchased the dual-trigger model (currently only available in the 1979- later version with canister-type trigger) please also check that both triggers give you the same timing setting. If not, please contact us for instructions.


11) The wires should be connected as follows:

BLACK Terminal (-) on right side coil (where black wire from points was connected, disconnect points wire.)
BROWN to frame ground (clean of paint to make good ground if required)
GREEN to terminal 15 on coil WITH green/blue wire
Check that the jumper wire between coils is in good condition and connected well.
If still no spark, check the tiny three-wire plug connector to the trigger plate. Make sure that the pin connectors are making a good connection.


12) Secure all connectors, re-install the fuel tank and go for a ride. Go far enough to get the engine fully warmed to normal operating temperature, at least eight kilometers on and off throttle load. Perform your normal carburetor adjustment procedure if necessary. You may find that you need to lean out the idle mix slightly for best running (that shows that you have stronger more stable spark) and that off-idle synchronization is much easier. 


Instructions created by Tom Cutter, Wedgetail USA, and  Rubber Chicken Racing