Good chance you have a piece of foreign material holding the needle away from the seat. Should be a gas shut off somewhere between the tank and the carb. Shut it off and remove the bowl after making sure all is clean. Hopefully this will solve.
Bolens, Shift On The Go, Riding Lawn Mower, Carburetor Is Flooding.Any Idea?
Could just be a clogged carb which is most likely. You have to take the bowl off and spray the jets and everything in there with carb cleaner. Use eye protection cause the spray will kick back in your face no matter how you try to avoid it. It would be easier to take the carb off and do it.
Check the carburetor has a hold in it on it is screw in tight or the gas tank might have a hold in it.
Plain an simple cracked bowl float or stuck needle valve an yes there should be a shut off before carb on fuel line