GPZ750 missing on 2 and 3

[GPRD]

I've finally got round to fitting the GPZ750A something engine into my latest project and I can't get 2 and 3 to fire correctly.
I've checked, swapped and changed the plugs, coils and leads, and they all work on pots 1 and 4. There is a good spark on pots 2 and 3, but not at the right time obviously. There is fuel getting through as its igniting in the exhaust or back through the carbs ( I've even had a flame come out of the air box).
The engine and carbs came together (from SteveW) the problem may lie with the igniter, I'm using one from a GPZ750R1, is that likely to cause the fire at the wrong time???
Any help would be appreciated, or suggestions to what it could be.
Cheers
Gary

[z1bman]

check your valve timing ?

[Crofty]

Gary, check you have compression, head gasket, ring problem or bent valves maybe?
If you have a spark thats good, you either have poor compression or no fuel getting to those two. No air leaks on carb rubbers?
If you are using the complete R1 system of pick ups and igniter it should work, i think these are like the 650 with electronic ignition. The A1,2 and 3 had a different pick up and a black box.

[z1bman]

gpz 750r1 uses a mechanical advancer + the zx750a has a static rotor. the zx750a ignition advance mechanism is controlled by the cdi. if you are using the rotor from the zx750a your ignition timing will not advance

[jimmock]

REV LIMITER!!!!

[steve.w]

gpz r1 ignitor wont work right ..

[GPRD]

Well, those of you who said it won't work with the R1 igniter win a prize!
I pulled the igniter off a Z750L4 parts bike I have, fitted it and it started on the button first time.
Cheers for the advice.
Gary