I am using a VM34-168 carb and have 159-n8 needle which works for RE engines. Also, last time when I got my pilot fixed, I had issues in the mid range. Everytime I revved hard and let the throttle go down it used to be perfect, right after the de-acceleration when I used to open throttle, the bike never used to respond to my throttle opening. There was this 2 to 3 seconds delay after the wide throttle opening. So I moved the needle notch from 5th to 4th notch and it was better, I have a feeling that something is wrong somewhere.
I think I will clean my carb and check for leaks. I am using a Uni filter, so no leaks there. Maybe the header pipe needs some inspection.