Atc 350x 400ex Carb swap

[Fixer_Upper]

I swapped a 400ex carb on my 350x and it cuts out upon acceleration. The air fuel mix. Screw is glued in so that’s another problem. I had to dremel out the intake tube going to the air box but otherwise nothing else really. Anyone know how to fix the acceleration problem?

[shortline10]

I’ve done a half dozen of the 400ex swaps but always used a new OEM
Carburetor , never an issue , no rejetting either .
Used carburetor ? Maybe something wrong with it ?