The rectanglar block on the front of your carb is a fuel pump.
If the lines going to it are cracked, or if the diaphram you see is brittle it will now work properly. You can buy a fuel pump rebuild kit to repair it. There are 2 different kits. P/N 693502 used on 4 screw mount carbs, or P/N 393397 used on 3 screw mount carbs, depending on which is on your engine.
Rick, October 2005