Originally Posted by HighwayThunder
...What I've noticed is that when that happens, the fuel filter will not fill, even with just the fuel pump on (refer to 2nd pic). My theory is that the unfilled part of the filter is a pressurized vapor keeping the filter from filling with liquid...
Your float bowls are vented to the carb throat. The floats only close-off supply when enough LIQUID gasoline lifts the floats. A constant flow of gasses will simply vent out past the needle valve as it remains open until the float closes it. - Dave