Each jet has a number stamped on it. So does the needle.
Has the bike always been this weak, or is this a new condition? A sure sign of needing a top end is an engine that gets progressively worse; harder to start and down on power. With the exception of atmospheric variations, jetting will remain static. It can be off some days and better on others, but it will not change to a worsening condition over time.
Before you start messing with the jetting or chasing other squirrels up a tree, have a compression check performed. After all, the bike is 7 years old so it must have a couple hundred hours on it, right?