starter wont turn and is hot .what might have caused this

Maybe the blade engage switch or lever was left on, which would prevent cranking. If not. Jump the positive battery terminal to the starter and it should crank over. If not, jump from a battery that you know is good, from a car. If still nothing, the starter is bad. If good, then you will need to trace the entire circuit from the starter to the battery. The solenoid, switches the battery power to the starter, when power from the key switch is sent to the small terminal on the solenoid. To test the solenoid, first make sure that you have power at its large terminal which comes from the battery. Then jump power from that terminal or the battery positive post, to its small terminal. You should hear a click and the other large terminal that feeds the starter should be energized. If not, then the solenoid is bad. If good, then continue tracing the power through the key switch to the battery until you find the break in the power path. All testing can be done with a 12 volt light or a voltmeter. Most equipment has safety switches in the seat and on the blade engagement lever. Check them by temporarily bypassing with a small jumper wire.

it was turning untile i wired the motor up then it would jump but when i took the starter off the motor the solinoid would click but the starter wouldnt turn. the old starter didnt have a ground should the starter have a ground. oh ya the wires going from the battery to the solonoid to the starter are hot also. i switched out a techumpse motor with a B&S 287707

If it is making a clicking noise when you apply power to it, the solenoid is good. Was there a grounding strap on the starter? The metal mount for the starter is your ground. If you wer trying to turn the motor and not have it grounded, the solenoid will start to get warm because you have power going to it. Try grounding the motor frame and see if it will turn then. remember NOT to turn the key too long.