RVF not reving out cleanly

[Drunkn Munky]

Got the trackbike started up today after a long long time since the last trackday and it seems very hesitant to rev cleanly through 5-6k, seems to clear once through it but doesnt seem right. I havent had chance to ride it yet and wont till later at the trackday so just looking for a few ideas if i have to start playing around with it later.
The bike was a little flat before around this rev range but i dont remember it holding back this much, the only things ive changed since last time out are the the slide springs for HRC items, added a carb tray ( it took its air feed from under the yoke before instead of the tubes so i thought adding the tray can only help), and replaced the wafer thin broken up air filter with a new piece of pipercross foam.
The engine was already ported, flowed and runs larger jets different front and back although i cant remember what size they are. It also runs no snrokle on the airbox and never has.
So any sugestions guys?

[CMSMJ1]

Is that in neutral or when riding?

[Drunkn Munky]

its in neutral mate, dont really wanna take it down the road incase it dies on me and that means pushing it up a fooking great hill.

just the add theres no speedo but there never has been so i guess that a resistor has been fitted at some point but i spose its worth checking this, where are they normaly fitted?