I HAVE JUST BOUGHT A 1995 B7100 HST WITH A 60" MOWER AND THE MANUAL SAYS THAT THE MOWER WILL CUT UP TO 4" . MY DECK HIT THE REAR STOP AND THE BLADE IS JUST 3" OFF THE CONCRETE. THE TIRES HAVE THE RIGHT AMOUNT OF AIR , AND I DON'T SEE ANY OTHER ADJUSTMENT WHAT AM I MISSING. IT LOOKS LIKE THE...