The clue is in the name CITYFLY.
I had one of these about 10 years ago and it was perfect for commuting into central London from out St Albans way. Tall riding position, good acceleration away from the lights, and decent fuel economy. I never got much above 40 due to the amount of traffic, so riding the Fireblade I also owned at the time for the commute was fairly pointless.
However, I do believe there is a cone shaped restrictor just inside the exhaust pipe near the header which falls out easily, athough I never tried it and doubt you'd get much in terms of performance messing about with it. Bear in mind if you DO mess about with it, and make a horlicks of it, you might not get much from a potential future buyer who'd want the bike for the same reason I owned one.
I'd leave it alone and wait for a bigger bike.
You have the right to free speech.........provided your not dumb enough to actually try it