Small Engines (Lawn Mowers, etc.): carb flooding, engine vibration, vent hole

Question
Have small Temcumseh engine. Gas is flooding out over flow hole in side of carb after about 10 minutes of running.  Took apart to inspect & clean, put back together, runs for about 10 minutes then floods out again.  Is there any answer other than replace needle & seat?  If needle not seating, why does it take so much time to flood?  Thanks.  Bruce.

Answer
If it doesn't flood out when the engine is not running, I would suspect there is an issue with the float pivot not working freely when subjected to engine vibration.  If there is a problem with the inlet needle, seat or float itself, it should be dripping fuel from the vent hole you are referring to at all times.  It could also be the needle and seat not sealing correctly when subjected to vibration.  The best bet is to replace the needle and seat and inspect the float for leaks and smooth movement when installed.  Hope this helps.