KTM EXC 300 no longer starts after carburettor cleaning

Servus, here’s what happened: I got a 300EXC from 07, with new fuel she jumped on then, then ran short with chuke but then went out again, sometimes with a nice loud detonation… Carburettor was disassembled and ultrasonic cleaned, and a fresh air filter came on now, now she doesn’t want to touch at all… would have packed a new candle now next time, does one of you have any idea what else it might be? Could it be easy at the carburettor setting evtl at the mixture? But as far as I know you should adjust the screw only when the engine is warm.. I read you should kick a few times even when the candle is turned out and without air filter, what sense does this have? Cylinder and piston are still relatively fresh Thanks already!