If you’re following the service manual here’s the steps you might speed past:
Set the pilot screw to two full turns out.
Set throttle adjustment knob/screw at a neutral position (no gap, but no pressure either) before you install the carb
The throttle cable slack might be improperly too tight after you installed the carb.
When you get the carb installed You have to hook up the cable end and then you have to screw the cable flange into the carb body. This can end up tightening the cable, opening the throttle a bit.
So I always then adjust the cable at the handlebar end—i set it in the middle, so sometimes have to back off the slack at the carb end.