The fitting in the manifold is to actuate the fuel pump.
The little hole in the carb, must be exposed to manifold pumping action also.
That is because there is an actual pump IN the Tilly carb. Thus the name, pumper carb.
Just file a slot from the hole in the face of the carb flange to the bore of the carb. Instant pumping thru
the carb.....as designed....end of problem.