Thanks for you friendly and personal reply. I believe your dealer is correct. You need a new needle and seat in your carb to keep fuel out of the oil. Might as well rebuild the carb with a full carb kit once you are in there. What type of engine does it have? If you are pressed for time, always run the mower out of fuel before putting it away. I think that gas in oil problem will then go away and you will have proven it is a leaky float valve.