Inside the 6254...Mixing Chamber, there is a ventura and also 6262...Air Valve. I have had this carburetor for over 45 years and have tried to get it to work many times. I bought the MTFCA carburetor book and found I am missing these parts. My question; dose anyone reproduce these parts, none of the vendors list them. Thanks in advance for any help Bob.

The "ventura" is part of the vapor tube, secured with a brass screw, lower section with screw collar attaches to hot plate cast lower section.

I haven't seen any re-pro air valves. Perhaps e-bay may show some vaporizor parts for sale on occasion.