Just going on the partial picture, it appears to be a zenith 28 or 228 series carburetor. If it is, there is a metal tag on the top of the float/fuel bowl with 2 numbers, and inner one and outter one. Then again the numbers signify a carter y or yf series. Please post some un-obstructed pictures of the sides and maybe one or two from the top. This would greatly help identifying the carb from long distance over the net.