trike

Cheerz buddy will give it a shot I took the needles out and noticed wear at the top of needles would this affect response it in any way and can you purchase just the needles on their own?

OK hi old school chaps,im a newbie to site and this be my first post so please be gentle with me haha this is such a common post probally,ive tried searching but can someone refresh me 1990 gsxr 110 stage 3 with straight through 2" bore,been off road now 5 or 6 years carbs are set 4 turns out on mixture needle 2nd from bottom (bottom is pointy end yea)145 mains cant remember how it ran but i do remember it juddering when cruising, ok best base setting would be?? im going to to lower needles 1 groove so that will be 3 from bottom and 3.5 turns mixture wot you reckon fellow suzi owners