Running like crap

I have an 04 fz1 and was running like a champ for almost 30k. What started as back fire on deceleration lead to running on 3 cylinders, now it is anywhere between 2 and 4 cylinders
Cold starting it causes it to run on one cylinder for awhile then will run on 3. While riding it, it’ll go back to all 4 cylinders when it’s above 4K rpms(most of the time) but will sputter if under that. Occasionally after doing some longer high rpm riding it will idle on all 4 for a minute or so. I’ve tried to figure it out but can’t. I’ve cleaned the carbs and checked the plugs (and replaced them). I did my research and I’m thinking it might be my coils, yet the 2 that don’t always fire are cylinders 3&4. I’m currently running seafoam through it and plan to check all the air passages and check for vacuum leaks. Any suggestions would be greatly appreciated.
 
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Get an inline spark checking tool they are extremely cheap on eBay couple dollars a piece. By at least two of them but 4 would be better. Hook them all up to your spark plugs and crank the bike you will know right away whether it is your coils or not. The spark checking tools will flash if they are sparking.

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update: I took it for a short ride and brought it back to try and work some of the seafoam through it. It now doesn't want to start again and will sprinkle gas out of the overflow tubes. I'm guessing this would probably be another case of the FZ1 bad carb O-ring?
 
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