I've been working on a Briggs Vangaurd 16 HP Horizontal Engine. After replacing the carb I had a massive oil leak coming from somewhere. When I checked the oil level it was way over filled. Today I put cardboard on top of the engine to see if it was engine or hydraulic oil. It was engine oil and it wasn't leaking oil near as bad as it was yesterday. There is a hose that runs from the bottom of the air filter housing into the engine. That hose had a large hole in it. I believe the oil was coming out of there. Is that where the oil would likely come out if it was way over filled? Tired of working on the thing.
Does the oil smell like gasoline at all? If you've had carb problems, there's a good chance that the float valve stuck open and filled your crankcase with gasoline. Now that you've fixed that issue (hopefully) an oil drain, dry out, and refill should get you going again. If the crankcase filled after the carb swap, then you've got float valve/seat problems with the new carb, if your oil smells like gasoline.
Does it have a vacuum operated fuel pump? They are known to loose a diaphragm and fill the crankcase with fuel.
If it will still run, don't use it with the oil diluted with gas, you'll trash the engine. If you just put a new carb on you need to make sure the float needle is working freely and shutting the fuel off when it should be...if you leave the air cleaner assembly off and run it you should be able to see if it's still dribbling fuel after you shut it off. It could have just been a fluke too, random piece of dirt, or a manufacturing chip left over causing those issues.
