ignition issue...

[emptypond]

So, I've got a kz750 4 cylinder. I have recently put it back together. My problem is, Cylinders 1 & 4 are not showing up as firing with a timing light. @ &3 are. I have blue spark in all cylinders when plugs pulled and grounded out against the block. I have swapped coils, I have checked voltages across the bike (all ok.) I have also swapped wires out, same wire set, different cylinders, and different wire set altogether with the same 1&4 issue. What could be going on for cylinders 1 & 4 to not be igniting the timing light when plugs are in the block? Potentially some ground out?

 

[HerrDeacon]

Are 1 and 4 cylinders actually running? Pipes getting hot? Have you tried moving the clip closer to the spark plug and also flipping it over so it clips the opposite way.

 

[emptypond]

Are 1 and 4 cylinders actually running? Pipes getting hot? Have you tried moving the clip closer to the spark plug and also flipping it over so it clips the opposite way.

I did try this, and also switched plugs between cylinders, and the issue still remained with 1 & 4.
1 & 4 pipes have not gotten hot. Only 2 &3. I know I'm getting combustion in 2 &3, but I haven't had it running long enough to dynamically sync the carbs