yeah seems like jetting to me since on almost all bikes you will feel the need to shift (to avoid exploding the bike) a whole lot sooner before you feel that you can't accelerate anymore, seems alot like a clutch problem too, try letting out your clutch cable a little at a time and test from there, and another thing, don't adjust your clutch cable while the bike is cold, because since it's a wet clutch the oil has to be warm for it to give the right reading, adjust after it is warm.