Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Problem is not the air filter, but the carburetor float and needle in the carburetor. The needle valve is not shutting off the fuel when no in use. You can rebuild or replace the carburetor, or you can get an inline gas shutoff and install in the line from the tank going to the carburetor. The gas could then be shutoff between uses, as the only time carburetor will leak is when not in use.
I see question is still open, did you see my response?