FWIW: My Farmall Cub (updraft, potmetal carb) used to ice up all the time while plowing snow at around 30F. Typically, icing occurs when the temp is slightly above the freezing mark. The low pressure created by the venturi lowers the temp inside the carb and, should any moisture be present, well, it freezes. Carbureted piston-engine aircraft have carb heat for such situations. For the Cub, I made a simple light-weight aluminum baffle that I attached to the engine just forward of the carburetor to keep fan air from hitting it - did the trick nicely. You might consider trying something like that for the A.
I have my A up in Western Washington for the summer and it’s running very rough. It runs like a top in Arizona. I’m being told (by a well respected mechanic) my carburetor is icing up from the moisture in the air and it has to warm up before it will run right. Any suggestions for speeding up this process or illuminating the need to for a warm up period? I know later cars (in the 50's) had a heat riser from the manifold to the carb but I don’t know if this option is available for the Weber. ANY suggestions appreciated. I’ll be driving it up to the BC meet and don’t want to waist gas and time warming before I can go anywhere.
