Sounds like your carb needle and seat agree leaking.
I just did a Briggs L head 12hp today. Parts 10.98 total.
Two main styles but basically most commonly a brass pressed in seat in carb and a rubber tipped needle valve that the float pushes up to shut off fuel.
Comon signs are empty or lower fuel than when you parked it, fuel in oil, fuel puddling in throat of carb, needing no choke to start, and smoke on start up after sitting.
Replace needle and seat then change oil and filter but I don't think yours has a filter.
