On test carb inlet check ball is leaking about half of fuel back into bowl. Ok at light to moderate acceleration but bad if stomped hard.

Guess, fuel level should be below that paper gasket line and above accelerator pump discharge ball seat.

Lowered fuel level some, 16/32 from top of bowl, still runs good.

Lower fuel more ,one more air hole in main well open to air.

Hot soak restarts much better. Now to mention this is just my guess work,on just one carb. There may be other factors at work here. Such has a dirty main system air bleed. A spec on where the liquid level of fuel should be would be help full,but can not be found. Holley had that spec for the 1920, carter does show one for there carbs.

http://imperialclub.org/Repair/Lit/Mast ... page07.htm My carb flunked the breath test. While engine running at idle a very slight amount of lung pressure applied at the bowl vent caused idle speed to increase[ time to clean idle tubes], more pressure engine stalled. Even at 2000 rpm lung powered increase in bowl pressure made engine go rich and run ruff.

capped off bowl vent.

Different carb in picture,air from outside should not enter bowl. If it does, will make carb go rich Green line is possible air leak.