CB70/80 Dizzy

Here are some pics of the GTti distributor. It has two reluctors and pickups for triggering and speed. The dizzy sends signals to the ECU for batch firing the injectors and providing spark for the ignition.

This is the armature showing the two reluctor wheels:

This shows the position relationship of the teeth. The 3 tooth wheel is offset to the 24 tooth so that pickups get a simultaneous pulse.

This pic shows the synchonsied teeth and the pickups. The pickups are fairly common items and rarely fail. Neither have the onboard ignitor.

and here we have the rotor view. The centreline of the rotor is offset to the three spoke wheel by 30°. In other words the three spoke triggers 30° cam rotation, before the centreline of the rotor aligns with the associated dizzy cap electrode/point. In timing terms the trigger is 60° before base spark. The dizzy rotates counterclockwise. There are no missing teeth to establish where No1 is, so you can't use it for sequential without some modifcation.

So if you are looking to sequential injection, one way to go about it is to grind off two teeth from the three spoke wheel to provide a synch pulse and let the 24 wheel do the timing. If you're looking to just go aftermarket you now know the trigger angle and the speed wheel angle increments (720/24 = 30°)

And before you ask, yes the bottom pickup doesn't have a shroud, because it's far enough away from the spark not to be affected.