Gas odor in Oil

[MorganScott]

How many ways are there to get the smell of gas into the oil, without much volume increase in the crank case, that doesn't include the carbs overflowing into the airbox and backfilling into the cylinders?  I suspect it could happen if the floats are set way too high, but I'm looking for some other ways it could also happen. Can this happen from letting the bike idle too long without good airflow resulting in the engine getting hotter than it should?

[Watcher]

The only way I can think is floats set too high and/or worn needle/seat in addition to a bad petcock.
Fuel overflows the carbs and floods cylinders.

[MorganScott]

The only way I can think is floats set too high and/or worn needle/seat in addition to a bad petcock.
Fuel overflows the carbs and floods cylinders.

I have experienced this for the exact reasons you mention here, bad seats, bad needle, and for somereason a petcock that does not stay off consistently, even after being replaced with bran new OEM.  The result being gas coming out the airbox drain line randomly, more-so on cold nights.  I think the drain may have got blocked or clogged at some point letting gas back feed to the crank case.  I have since flushed and refilled the oil, but may still have some remnant smell, just wondering if there are other ways for this to happen, thank you