my bike runs fine at low rpm but when it hits 5000rpm it misses and won't go any higher. i already know its not the rev box or rectifier. please help

 

in neutral or in gear, or both?

how do you know its not the CDI? A bad CDI can cause this, as well as a CDI with a loose connector that may not be plugged all the way in.
but if you've already ruled that out, you might wanna pull the head cover and confirm proper cam timing, as well as a good visual inspect of your cams and cam chain tension. the most recent story I've heard concerning this same symptom of lack of rev led to the discovery of a broken cam - snapped right in half.

 

Maybe a lower tech answer. I had a problem similar to this. Mine would cut out, sputter and miss at higher rpm especially when climbing dunes. I tested everything which checked out fine. Turns out I had a small piece of what looked to be gravel in the float bowl. Luckily not big enough to go through the jet but large enough to block it off under acceleration. Take your float bowl off and look in there, also make sure your jets are in right. Also check your fuel filter in the tank it might be plugged up.