Ok so maybe you guys can help me out I checked old posts and couldn't find much that would help me in my situation. 91 250r running closed airbox k&n with outerwears v force 3 .40 over piston coolhead with 22cc dome stock porting an full fmf system. Stock carb with 32.5 pilot which I'm gonna bump up to a 35 (slight bottom end hesitation) 280 main and needle on middle clip. I want to run the lid open but I'm having trouble with my plug chops seems to me I'm lean and I can only do it in fourth no room for 5 or 6. Really want to run open lid but scared of going lean and melting a piston. Everything i listed is brand new so no worn out parts for sure. Temp right now is about 40 and I'm right at sea level. What's a good starting point for me to run open lid. Thanks in advance guys

i would go 1 size bigger for the air box lid, and maybe 2 for the temp, its better to be rich then lean.
make sure you go bigger on both jets though

should put you in the range. you might have a ruff time getting it started at first.
your gonna have to turn air screw to