1989 Jeep Cherokee Starter motor

Im not sure what a stacato noise is, but you may need to inspect the flexplate (flywheel) to be sure the teeth are all intact. Also test for full 12 volts down at the starter on both the main cable and the trigger (small) wire. Does the starter try to turn when key is on but not in crank position? If so be sure the small wire isnt touching the main cable at the starter motor. Also might want to count th enumber of teeth on the new and old starters to be sure they are the same