Have you read the carb guide in the tech section? I don’t know which fuel screws you got to replace the old one, but that could make a difference. Do you have to use the choke to start the bike? If not try turn in the screws a 1/4 at a time until it starts idling good. If you use choke to start it then do the opposite with the fuel screws. One more thing if you actually drilled out the ports and enlarged it this will cause an imbalance.