Cutting out at higher rpm

If the engine is the DOHC 16 valve engine inline 4, and has multiple carbs, then I have 2 suggestions for you, First thing I would take the carbs off, as a whole rail, and have them ultra-sonically cleaned at a shop, and the diaphragms checked in the tops. After that, you need to have the carbs synced while on the bike. I have a GSF600S and it was basically opposite your problem, it had a sputter in the low rpm range, and the carb syncing fixed it, and they honestly weren't that far off. The way those carbs feed fuel, if one is giving too much fuel then it will cause ur plugs to foul, or flood that cylinder, causing the issue. For the carb syncing I suggest building this tool, which I did for my bike.
http://www.powerchutes.com/manometer.asp
It's a liquid column differential manometer, which very accurately and sensitively measures the vaccum on the different cylinders of the engine. The only other thing I can think of is your ECM, which controls the engine, and incorporates your rev limiter. These are pretty pricey, so I would do the steps above first.