using a know good battery hook up a jumper lead to the thick red wire that goes to the starter being carefull not to touch the body of the starter to the + of the battery.
hook this wire up first then run the other jumper from the battery to a good earth, I like to use the oil drain plug.
You will ge a big spark when you do which is why you doo it in the order listed.
If the motor spins the engine it is good.
Now my turn.
Why do you ask this question ?
https://www.google.com/webhp?source...e=UTF-8#q=how to test starter on lawn tractor
Rule out solenoid, loose wiring including grounds, relays, safety switches before removing starter.
Remove negative cable from battery & tuck away from negative post, remove starter & take to auto parts store & have them perform " starter draw test" should not cost you anything.