Ah, gotcha. Would that also cause the weird idling issue?
Flooding, too much fuel. If the carb isn't dumping fuel, it can come from the gas in the oil getting to the combustion chambers past the rings and valve guides.
A little story -
Small block Chevy starts running bad and blowing black smoke. Ace mechanic is all over the carburetor for quite some time, and getting nowhere.
Happened to notice white vapor coming from vacuum lines, dipstick, and oil cap. Whoa! A gallon overfull in the oil pan ... lots and lots of gas. Fuel pump was leaking gas into the oil pan. New fuel pump fixed it.