Bought this 1995 cbr600 with 26000 miles less than a month ago and it ran great. I was able to rip it up and down the street no problem. About two weeks ago I was riding it and after I shifted into 2nd and give it more throttle it started to cough spit and backfire at around 8000 rpm. I got it back to my house and started to work on it, first I did spark plugs, no help. Next I put seafoam through the carbs, no help. I should mention that it idled just fine and could rev up to 12000 rpm no problem when parked and in neutral. I read some forums and someone mentioned ignition coils so I did that. Also cleaned and oiled my air filter, not sure if I did it right cause I've never done it before. Now it barely runs and it only runs if I keep the throttle on and at about 1500 rpm and it sounds like it's running on 3 cylinders. I checked the plug boots and wires and they're on there good and tight. My idea is that now it's running lean or one cylinder isnt firing. I really want to fix it myself and fix it quick cause I'm a college student and I dont want to let it sit while its non running so please any ideas welcome

 

here's a link to my PDF's for this bike.

https://www.dropbox.com/sh/h1a6fqjln...FWGpQqw6a?dl=0

open the one labeled "CBR 600 F3 manual" jump to chapter 16, page 312 i think it was, it has what the resistance should be of the cable's, plugs, and coils should be, that is where i would begin.

 

I went ahead and tested my new and old coils like the manual said, primary resistance on both sets is about an ohm higher than spec. I'm horrible with electrical and wiring but I feel like 1 ohm higher shouldn't make a difference but maybe it can?