howdy Guys, I am new around these parts and had a question about a mower I put together a while back. its a 16hp twin briggs on a MTD/Craftsman chassie. heres the problem, when I start it and run it its smooth at first and then acts like its not getting gas. I have torn down the carb and cleaned it and have pumped out the tank and refilled with fresh fuel a couple of times searching for what is wrong. I never have found the problem. if you guys have any ideas I could use the help at this point.