carb boiling over

[jason nv]

ok my fordbarn friends here is my delema. when the weather is cool her i dont have a problem. my 8ba runs like a top. when summer comes and it warms up i have a problem where once my car hit 180-190 deg and i stop at a light when i take off it seems ok but then stumbles. it will sometimes even die like its out of gas. i believe this to be a heat problem with the gas boiling or vaporizing. i inclosed a pic of the side of my carb (brown color) that wasnt there when the weather is cool. at this point im not running a hood on my 51 and it still does it. any ideas on if this is the problem and what i can do to remedy it. i have even put an electric pump to help out when it happens but it doesnt seem to help. normally i run the mechanical pump. thanks