Can you tell me why I would be leaking gas from the valve even if I have cranked the dump screw all the way in? I have come close to stripping it I tightened it so much. The other weird thing is that if I shake the quad side to side, gas dumps out the valve even worse! Maybe that is normal, but just a simple shake from side to side shouldn't dump a stream of gas out the dump valve I'd imagine... Thanks in advance for any light you can shed on my situation..

 

That screw only blocks the drain function, not the vent or overflow function of the carb. Theres is still an open tube which cant be shut off. see my picture 6 in my gallery. The brass tube sticking up is the vent/overflow.
Either the float level is set too high, or you have some crud in the float needle and seat, which is holding the flost low, and allowing the gas to flow and fill the float bowl higher than it should.
Try this first, before pulling the carb apart. Open the drain all the way, and put the tube in a can or something. While the gas is flowwing freely out the tube, lightly rap on the side of the carb with a chunk of wood or screwdriver handle. It might dislodge the crud. If this doesnt work...the carb will need cleaning and or float needs resetting to the correct hieght.

 

Had same problem on my grizz. I found my float was out of adjustment