91 ninja zx6d

starts up and runs but will not rev up past 4000 rpm starts bogging cleaned out carbs tank and fuel line and still runs the same,i can let it sit and run for alittle bit then it will die and really hard to start back up ,bike was running fine untill took on a long trip then it just started doing this any help would be very helpful , think its not getting enough fuel open it all the way up would only rev up to 4000 held it open and dumped gas in carbs and it reved all the way a few times untill fuel was burned up

Brian, It sounds like the bike is running on two cylinders. See if you have spark on all 4 cylinders. Check your coil and connections if you don't. The most likely items to fail, are the coils, the ignition triggers and the least likely is the ignition control unit. The spark is in pairs of cylinders on that bike. one coil is two cylinders and the triggers each switch two cylinders. (1&3 and 2&4). Hope this helps, Paul