Hi all, new to this forum and wondering if anyone can help me figure out what's going on. I have an older Sears mower with the Kohler 20 hp. Mower wouldn't start this spring so I rebuilt the carb, replaced the plugs and fuel filter and air filter as well . Started up great and ran like a top. Runs for about 20 minutes then dies. Won't restart for a couple of days, then does it all over again. Does this sound like a fuel pump issue or plugged lines? Or...? Any tips will be greatly appreciated! Thanks!