Inside the bowl on the bottom of the carb there is a float. This float regulates how much fuel goes into the carb. The float rest on a needle (float needle) and when the fuel goes into the bowl the float will rise up raising the needle and stopping the flow. If the needle is jammed with grit or slag from the factory or the float has a pin hole or crack, then the needle will not stop the flow. Thus, seeing the fuel is higher than the bowl, it just keeps flowing, maybe into the engine, maybe out the intake side of the carb.
think i need a new carborator and i need to open up the engine. (new engine) i start going at a decent speed i release clutch and throttle i hear the engine flutter and start then it almost always dies and when it works the throttle does not throttle it just stays on kind of