Check that you have fuel in the float bowl by opening the throttle while you look down the venturi. There should be a shot of gas as you work the throttle. If not, you don't have gas in the float bowl, or the accelerator pump is shot.
I'd also check for vacuum leaks.. loose hold-down bolts or bad carb gasket, PCV hose knocked off by some fumbling around. You know the drill.. look for what you might have bumped. Even the coil wire to the dist...
tom