Bike chocking and dieing at high revs

[Batman]

When i'm at high speeds or accelerating quickly my beauty will choke for a second or so and die in revs a bit. It isn't the nicest feeling and i was just wondering what you guys think it was so i can get it fixed straight away. Done many things to a bike but only once i've found the problem

Many thanks guys! If you need any more information then just post what you need!

[CaNsA]

It's called a flat spot mate.
At what revs will it stutter?
What ai filter do you have in there?
What exhaust are you using?
Have you pulled the plug from the airbox breather pipe to drain any water?