Dose this sound like bad jetting?

Oh goody, a noob with a fueling question - yes, I even give myself the shits sometimes..

Anyway, the bike is uncorked and running whatever jets they give you from the dealer according to the last owner. Im yet to strip everything down to check whats actualy inside but plan to this weekend.
Now it starts easy and runs smoothly, but it seems to be a little flat in the middle then launches into the top end.
If I had to take a stab at it, I'd guess is running a little lean in the middle then coming good when it starts drinking off the main. How's that sound?
It's been years since Ive had to worry about jetting anything (ah..sweet fuel injection..) and cant remember which stage of the jetting governs the transition from certain throttle openings.
I know theres plenty of 'use this jet' info out there, but I just like to the 'how and why' as well.

Call me an anorak.

Or anything else you like..

Dunno how this got bumped, but anyway its sorted. Turns out there was a teensy piece o crap in the bottom of the bowl.
Now running a Swiss cheesed and meshed airbox lid, carb fix as per Borynack and a .178 main.
Lovely..