Hello I have a cbr600 f2 with stainless steel manifold, micron exhaust and k&n filter. Dynojet needles with stock washer with "38s" pilot and dj128 main jet, fuel screw is out 3 turns. Carbs are all clean and synced. I have 2 setups and neither are great.

With above setup the bike almost jolts forward momentarily at 9-10k rpm then recovers to 12 etc but pulls great up to this.

If I add a shim to the needle then the top end has no stutter and is fantastic, BUT from 4-6k rpm it seems to bog down.

Any tips, thank you

based in uk