I HAVEA JOHN DEERE LX279 MOWER W/ THE KAWASAKI 17HP ENGINE----RAN FINE LAST WEEKEND,PUT IT AWAY WENT- TO START YESTERDAY,TURNS OVER ,GAS IS GETTING TO CARBURETOR,REAPLCED PLUGS ,BUT NO SPARK TO THE PLUGS.CHECKED THE COILS NEXT TO EACH PLUG WITH A 12V TEST LIGHT---HAVE POWER ON BOTH TERMINALS OF EACH COIL,BUT NO FIRE TO THE PLUGS. ANYONE HAVE ANY SUGGESTIONS BEFORE I START REPLACING A LOT OF EXSPENSIVE LOOKING PARTS? THE BLACK BOX BEHIND THE STARTER-IS THAT THE SPARK CONTROL BOX? CAN IT BE CHECKED?