Try opening the pilot screw a half turn more and see if that makes a difference.
Check for air leaks around the rubber boot from the air box to the carb.
Spray WD40 around the connection while the engine is running, and see if the engine rpm increases.
Check to see if the small spring at the top of the main fuel needle is still in place.
Sometimes it will fall out during reassembly.
Check the plastic spacer on the fuel needle. It should remain at the top of the needle, and not easily slide or move.