The track tension on a 2003 Arctic Cat Firecat 700 EFI with a 151-inch track should generally be set to allow about 1 to 1.5 inches of sag when you press down on the track midway between the front and rear wheels. It's important to ensure that the track is not too tight, as this can cause excessive wear on the drive components. Always refer to the owner's manual for specific guidelines and maintenance recommendations for your model.