You almost certainly have too much fuel pressure. I'd try to keep the original gear.. The fuel pump and the carb were made to operate together. Gravity fed carbs have bigger float needle jets than carbs with pumps. You should set the carb float to specs if it's a carb recommended for that bike (bikes with tilted carbs have different float settings than flat mounted carbs), or to a setting that will have the fuel at the right height if it is tilted, and then try running it with a temporary gravity feed.

Its hard to Judge whats really going on. Not all chinese carbs are built the same and not being familiar with the one you have is difficult. I set the float level as the factory setting suggests which means the float is parallel with the float chamber lip. Then adjust it out from there with the air fuel mixture screw..The only time i vary that adjustment is if gas is still overflowing from the float chamber which theoretically shouldnt happen unless there is a discrepancy in the needle and seat. If you bought this carb new i am assuming it is right one for your quad. If not i would not spend much time on a aftermarket carb. The cheapest solution would be to get another aftermarket carb, my expierience is some work great but most dont. If i was doing it and wanted it up and running quickly i would try the cheapest solution, but continue to look for an OEM carb to rebuild and get it back to factoruy specs with oem jets and needles.