How do I remove the tire when I take off the main nut. Somthing seems to be holding it on still. It is the front wheels

I have a Honda GCV160-AS3A on a Craftsman Mower 917-378501. The carb keeps leaking after shutoff. I have tried a new carb and it still leaks. I have the gaskets that go between the carb and the engine installed with the hole on the right and the gasket that goes between the air filter housing and the carb on the right. I have also installed all new gaskets. The original carb leaked gas all over and the new one has gas seeping around the bowl gasket. I am getting ready to try a third carb off a Husqvarna mower and see if that works. The new carb came from a distributor. The original one came with the mower. I have also cleaned the gas tank and installed a new fuel line. I installed a new needle and seat on the original carb. I would really appreciate some help with this one.