New carb filter and great spark gas pours out of carb still no start

92 marathon old carb was just pouring gas out of over flow with no start and only when trying to start installed new carb the other looked pretty bad when I went to rebuild new gas new filter it's doing the same thing gas pumps out over flow have good spark no start and half tank gas on the ground?

Update 6/8 so I proceeded to rebuild old carb and put it back on at first it was overflowing again with no start so I disconnected the pressure line from fuel pump thinking it may start with the fuel in bowl and it did! …. after running a few minutes it was starving for gas at this point I put pressure line back on pump and it's been running fine since?