It sounds like you might have worn bushings on the throttle shafts. For this, you'd have to scrounge for bushings to fit this carb and let a machine shop install them.
However it could also be as simple as the float set wrong, or the fuel shutoff valve being stuck open. I think this could give you enough pressure to 'squirt out' a bunch of gas from several places. A simple rebuild would fix these probs.
If it were me, I'd get a rebuild kit and see if this fixes it.
