Tractor starts and runs fine for about half hour and then it stalls out. I disengage blades , put it neutral, press the clutch down and it starts right up and runs for about 5 to 8 minutes then stalls out again. This process repeats over and over till I finish mowing. Please HELP!!

Hi, I am going to say you have a fuel restriction. Whether it be a slowly venting gas cap(unlikely), a partially clogged fuel filter(quite probable), a partially flattened fuel line(possible) or a weak fuel pump(possible) the description seems to point to one area to look fro the problem.
Peace,
Clarke