Chosen Solution

mower runs when the clutch is in,and dies when you release the clutch, why?

There is a safety switch under the seat which requires that you be sitting on the mower while it is running unless either the clutch is depressed or the emergency brake is applied. Make sure the wires under the seat have not become disconnected. You may need to test the seat switch with a meter to insure that it is working properly. They are usually quite easy to replace.

Transmission or drive shaft bent or locked. If you put enough load on an engine you will kill it. If you accept this answer please return and mark it. Good Luck, N.