Check the 2 ears where the pin that holds the float in place. On the face of that metal where float pi it’s up and down should be very smooth. With the float in place try pivitoing it up and down real gently to see if it sticks. Also with everything in place and carb held upright pivot the float and make sure needle is not sticking. Have seen some where needle will actually stick closed when float goes up and then when float drops needle won’t come down. In that case carb runs out of gas. Then you pump it up and pressure releases it then it might not stick again for awhile. When you pull float, pull needle and check rubber tip on it for distortion. Then if it looks suspect I’d order float and a new needle and seat.