you have DIRT in the carb needle and seat . that is why its flowing over and flooding the engine . you can break the pistons and rings with excessive fuel in the combustion chamber . squeeze the fuel hose shut with a tiny pair of needle nose vice grips . this will stop the fuel pump from flooding the carb and the engine may run for a few seconds . until the fuel level in the carb drops . you could then release the vice grips for 2 seconds . see if the carb overflows again . i have to take carbs apart several times a month to clean out debris . sediment . holds the needle and seat open . as does teflon tape . the other issue is did you get compression on the number one cylinder and verify the rotor is pointing in the proper direction . try reversing swapping the spark plug wires in the cap . move each pair 180 degrees .