1981 kz650 csr only getting power two cylinders

Hey everyone, I got something that has been annoying over the past week or so. Bike started having trouble starting up and would only start on cylinder 2 and 3. It has dyna coils and electronic ignition (previous owner upgrade). I swapped the coils and still no spark in #1 and #4. Checked the gaps on the electronic ignition pickup and they were fine. Next step is to test the cdi box and the stator?? Do y'all know how I go about that? The weirdest part is the first thing I did was clean the plugs and the bike started up fine and rode good for an hour. Then after sitting for an hour it was back to s old tricks. The bike has always ran a little shitty and backfires a bit if that helps the diagnosis. Any help would be greatly appreciated. We have also gone through and tested electrical resistance on all wires to make sure it wasn't something stupid like a faultybutt connector.

The manual will have a procedure for testing the ignitor. It will also have a simple procedure for testing the ignition pickup . You'll need a multi meter for a resistance check.
If you need a manual click on the "Articles" tab above, then service manuals and there is a pdf for 1981 650.

When you swapped the coils did you also swap the red ignition wires? Just wondering if problem may be with the red ignition wires. If you left the wires attached then disregard