84' vf750f missing at 1800

Hi everyone I'm new to the forum. Having a weird problem with my 84' vf750f . Recently I changed my clutch. Complete whole basket the works, came from a donor vf700f with way less miles on it. The starter clutch that came off the donor 700 seemed tighter too, so I swapped it in also. bad move, different timing on 700 starter clutch than the 750. So it ran and idled. But would cut out at 1800 like it's hitting the rev limiter. So I swap back in my old starter clutch and wouldn't you know same problem. Checked my pick-up coils because that's the only ignition area disturbed in the process of changing the clutch. Looked good but didn't measure the right resistance, put a new one in. No change. Swapped in some known good ignitors, no change. Ignition coils checked out ok for resistance secondary and primary. Swapped em' side to side no change. Still hitting big miss at 1800 and not revving above this. Pulled carbs and found nothing wrong there. The bike was running great when it went on the bench for the clutch change. So now I'm pissed and have lost focus. Any helpful hints would be appreciated.
Thanks
caveman

 

Check the connectors at the ignition boxes in the tail section. They will get dirty and not make a good contact. Sounds like one of the ignition boxes may be bad. Are all four cylinders firing? The pulse generators are gaped between .012"-.036". Just some thoughts.