Small Engines (Lawn Mowers, etc.): briggs 18.5hp, craftsman lt2000, gas tank

Question
Hi Nathan. I have Craftsman LT2000 (B&S 18.5 horse engine) and it recently ran into some problems. The fuel was contaminated with water, which got into the caburetor and the engine. I took apart the carb and cleaned it out thoroughly, replaced the fuel filter, flushed and changed the oil and filter. It was running ok after all this, but now it's running for about 30seconds and then cutting off. I also just added some Gumout last night, but can't get the engine to run for more than about 30 seconds continuously. The model number is 31P777-0492. Any ideas/suggestions?
Thanks!

Answer
did anything get in the gas tank that may have gotten back into the carb that plugged a jet I would try and clean the carb again that is what it sounds like to me and also check the spark make sure you got good spark maybe wouldn't hurt to clean the coil up a little and regap it use a index card to gap it to the flywheel thanks let me know how you make out with that