I have a 16.5 Kohler on a Craftsman tractor. It is not flowing gas all the time to the carburetor. If I let it sit or (Not a good habit) blow into the gas tank the filter will fill up and it might be fine for the rest of the mow or I might need to do it again. I just installed a tune up kit because of this problem. Wozzy in IL.

Well, you could have something inside the tank blocking the flow of fuel, or in the fuel line itself.

I checked the tank again and replaced the hoses. Still not flowing. I am wondering if the carb is supposed to draw gas from the tank and I may have a vacuum leak. Any thoughts anyone? This not really an answer kind of a brain storm or maybe just a cloud.

Could also be a faulty fuel tank cap not venting properly.