ignition pickups & igniter boxes

Hi everyone, I have a 77 z650 but at the moment it has a gpz 750 motor installed with an optical ignition unit (newtronics) but ive also built a 810,6speed motor that I would eventualy like to fuel inject, the ignition I would like to use is a cross between the gpz pickups married to a kz550 igniter box so I can get away from the manual advance & retard & also swop out other Kawasaki igniter boxes with different advance curves & cut outs, ive posted a picture of what I have at the moment but does anyone see any major reason why this would not work?
regards theranger

pick ups & igniter

You don't show a Kz550 igniter box in the photo.

The igniter box in the photo would be a Zx550 if it is from a 550.

The pickups on the left side of the left side of the photo must be used with a mechanical advancer. They won't provide the required signal to run a Zx igniter box.

The pickups on the right side of the photo will provide the correct signal for the Zx igniter box, but the advance curves for the 550 are different from the 750, if I recall.

The Zx advance curve is a combination of the big, round rotor with the rectangular tooth and the electronics in the Zx igniter box. The tooth affects the curve.

Hi thanks for the reply Lou, the igniter in the picture is part number 21119-1113 off a gpz 550 some confusion caused by the fact not all models were sold in Europe (I'm in England) so my z650 would be a kz in America & I may have specked the wrong model prefix sorry ,anyways I have seen a previous post from you that showed the ignition curve from this igniter & it looked usable to me & I believe other Kawasaki 21119 prefix igniters could be used to maximise various ignition curves, however all this is academic if its a non starter technically to splice the 750 pickups to the 550 igniter box, doable or not?
regards theranger

You have enough parts in the photo to make a Zx electronic-advance ignition, but I don't think the advance will exactly match a 550 or 750 curve, it may be some hybrid in between.
I haven't actually tested a 750 system, but I tested a 550 system and the tooth of the rotor will play a part in the advance curve. So does the igniter box.
I'm only assuming the tooth is different because there is no other reason for the rotor to have a different part number. (Kz/Zx 550 rotor/advancers are swappable with 750-fours.)

1984 Zx750A2 rotor 21007-1069
1984 Zx750A2 igniter 21119-1075

1984 Zx550A1 rotor 21007-1104
1984 Zx550A1 igniter 21119-1113

All you can do, really, is try it and see what you got with a timing light and a precise external tach.

Smaller engines seem to tolerate more total advance so try to limit the total advance on the 750 to whatever the FSM says is the limit.

If you need help determining which wires to splice where let me know.

Cheers for that information,
Regards theranger

Cheers Lou, just to let you know fitted the gpz750 pickups with match up to zx400c wiring colours to the gpz 550 igniter then to my z650 (kz650 to some) & hey presto the motor starts & runs, not taken out on a road test due to not fixed up securely yet but now I know we have a runner that will get sorted.
cheers the ranger

That's great! Thanks for the update.