needing carb help!!

[madwolfcody]

i recently just purchased a 2022 motomax 250 and replaced the stock carb for a nibbi carb currently last night i was running a 130 main get and 40 slow jett bike ran great then today i start the bike up with no problems but at 5000 rpm bike falls on its face and spit and sputters the needle is on the 4th setting and the a/f screw is 2 1/4 turns out im running stock air box / stock exaust im located in the dallas texas area and i have adjusted the valves as well to spec any help would be great.