Capping of the enclosed bowl vent valve hose fitting defeats the purpose external bowl vent valve.
The purpose of the vent valve is to provide an external path for the fuel bowl evaporation to improve hot starting. Without the idle bowl vent valve, all fuel vapors collect in the air cleaner through the main bowl vents, creates an over-rich hot start condition. Problem with six-packs, two other fuel bowls without external venting, still a beast to start hot with the air cleaner in place.