SIP staff ADVICE please!

I would be most grateful if you could spare a moment to to divulge some of knowledge re; suggested carb set up .

The spec i am running is an ET3 primavera

Polini 130 (cases ported, but barrel ports unaltered )
Rotary valve mazuchelli crank.
16 degree timing
Carb 25PHBL , D22 needle (2nd clip from top) , AqAvAs264 atomiser & 95 main jet.

Problem : engine is rapid up to half thottle then above half throttle it seems to get sluggish and won’t rev out. I’ve tried a 92 & 90 main jets with the same results aswell as two different expansion chambers (simonini d&f and sito banana).

Do I need a different needle jet? would an X3 work? I’m stumped

Ps. Plug colour is perfect

I was a bit concerned about jetting that low with set up I’ve got, but suppose experimentation is the name of the game. Its the perfect plug colour that made me think the main was ok. Theres a fair bit of spit back on the bellmouth though.

I’ll give some smaller mains a go.

Ps. I hardly touch the P2 now I’ve re discovered the smallframe and its superior handling powers

From half throttle to full is fueled by the main jet. Have you tried an 75-78- 80-82-85 etc. main jet? Main jet size is partly dependent on the extraction and reflectives of your pipe so a different pipe will usually need a different m/j.