Hi. I have Novarossi Top .21 on my 977 and it sounds like it bogs at low end and I can't seem to pinpoint the problem. At beginning of race, it's fine and after a few laps, when I hit throttle out of corner, it doesn't accelerate right away (I mean it goes but slower acceleration than desired) but it takes about 0.2-0.3 seconds before it takes off fast, like booooBOOOONG.. And it definitely gets behind the other cars every corner because of that.
I thought it was clutch gap or spring. The gap is 0.6. Spring is hard. I put a new one. And I thought it could be LSN being too lean. So I richened more and more and checked every time but it only slowed down the car and didn't fix the problem. What could it be? Thanks in advance.

P.S. I've done pinch test and idling time to check proper LSN setting and temp check after 5m running and it was 225-240F.