Well if you have gas in the cylinder then it almost certainly is in the oil as well. IF the oil is contaminated with gas, engine will likely fail as many do. You need to install an inline gas shut off valve and use it when the engine is not running.

These engines typically run lean so you do have a problem. You may need to check that the carb float doesn't have a hole in it. If it does, you should be able to hear gas sloshing around in it when you shake it. Check the seat but unless it has a big pc of debre stuck in it, even a leaking needle and seat shouldn't leak so badly to caust the symptoms you describe.

Walt Conner