tops out at 115mph?

[JoeZXR]

So I have a zxr 400l which has had an SP engine fitted and the previous owner has a dyno print saying 64bhp and claims the bike is fully derestricted. Now here my problem...
If I try to go as fast as I can the bike goes so well! Revs too 14k nicely but as soon as I get to 115mph the bike bogs and slows down wont rev past 10k and wants to pull but its almost as if its not being allowed to go faster??

Please help I have no idea what this is, the carbs arnt restricted and I have mph clocks fitted and a custom yoshimura exhaust that the bike has been professionally set up too run fine with, my only guess is the clocks could have been swapped when I brought the bike for a lower Milage sale? Does this sound like a clock restriction?,

Any help please thank you

[RedexRobB]

Joe, please search the forum as this has been asked many times. There's a dedicated forum for restricted zxrs. Thanks.