Hi Buddy
You more than likly need to rejet. I`ve been trying to find someone to tune mine not easy but i`ve found http://www.motorcycleweaponry.com.au/. at mona vale they seem good there. he will dyno a NSR the only one i can find they will let you go in and help them (wich will save cash) .The knowlage you can get out of it would be handy as well.