Matty, if your epoxy glue will bond properly to both the carburetor and the small barb or elbow you want to fit, and if you put a fair-sized fillet (i.e. a substantial ring of epoxy to join the barb to the carburetor) for a few mm all around, you can fix it in a way that will be stronger than the original carburetor (which isn't saying much). The problem is that there are many kinds of plastic that epoxy will not bond to, and unless you do a test piece first, you won't know whether you have a fix or a mess.
