2010 EC 300 exhaust change problems

[Ryan.Ager]

Hey guys,
I recently changed to a DEP full system, replacing the original system
For the first ride, it felt great, more responsive and crisp
Second ride it felt like the bike would bog down in 3rd when opening right up, but mostly would clear and rev out
I took it out today, and it just wouldn't rev past half throttle at all.
I played with the mixture screw, which didn't really improve it, so I adjusted the needle, its now on the first notch, and is running better, but nowhere near as good as before.
I'm guessing it needs re-jetting, although this is where i haven't a clue where to go next.
Any suggestions much appreciated.