Electronic ignition questions

[fester]

Guys I just need to clarify the workings of the digiplex ignition a bit more. This is for my 89SS.

I want, for various reasons, to use a late model injected tacho on my 900 SS. I am looking at designing a wiring circuit to correctly trigger the late tacho as they normally get a trigger from the ECU.

I have ascertained from one source that the late tacho requires a 12 volt signal so that makes it a little simpler but the late bikes generate 2 signals per 360 degree crank rotation.

I am assuming the early bikes with the digiplex only get one trigger signal per rotation, can someone confirm. I am expecting I need to get a wiring circuit that multiplies the signal but I need to know if I am multiplying 1 x 4 or 2 x 2.

If anyone's got any clues on a circuit too that wouldbe handy.

[Tamburinifan]

1 signal/rev.

[fester]

Thank you Gert but to clarify are you saying 1 signal = 1 rev on the gauge or 1 signal = 1 revolution of the crank. It is the later I need to confirm - How many firing signals are sent per crank revolution.

The injected bikes send 2 signals per revolution. Not sure if they actually fire the plugs twice but I assume that is what is happening. It's early injected bikes so we are not talking twin plugs heads.

[Tamburinifan]

1 signal = 1 revolution of the crank.