Small Engines (Lawn Mowers, etc.): Simplicity ztr with 16hp Kohler, empty gas tank, simplicity ztr

Question
I returned from vacation to an empty gas tank and a seemingly dead battery on my simplicity ztr.  I replaced the fuel filter because it was leaking.  Once started, I noticed I could get off the seat without it stalling which it would not let me do before vacation.  Once started it ran for about 1 minute before surging and then dying.  I was able to keep it running for a few seconds longer by choking it.  I pulled the airfilter and a pool of gas had formed underneath and was bubbling.  I took off the carburator and check to make sure the float was loose and jet were clean.  It seemed clean.  I put it back together and it did the same thing.  Once it dies, I can start it back up withing a few seconds.  It will then run for about a minute and die again.  It will continue running for a long time if on a low idle.  I get the feeling it may be electrical but?????  Sorry for such a long question but I wanted to give as many symptoms as possible.  Any ideas.

Answer
The second it dies get off and check for spark.  I'm guessing you will have plenty.  The reason the tank was empty was the carb was leaking into the crankcase.  Buy a carb kit and rebuild.  CHANGE THE OIL, there will be fuel in the crankcase.

Most people bypass the seat switch anyway.