The carb's float needle and seat are not properly sealing causing more gas to enter. You need to clean or rebuild carb, also check your oil for gas.
I am a john Deere Mechanic and your carburetor bowl needs to be taken off and your seat taken out and inspected and put back in if in good shape if not then replace it. Another problem could be the electronic fuel solenoid is sticking if it's equipped with one.