/6 stalling

Could it be the air fuel screw needs to be adjusted I know when playing with mine if I go to rich It will suck air from the PCV valve and then stall. I could see adding the air cleaner causing it to get less air and be adjusted wrong. I would try going lean a bit w/o the air cleaner and then put the air cleaner on and see what happens. Just a theory I'm not very good with carbs yet.