You have probably done some internal damage to the starter by running with the drive engaged that long. The gear is supposed to overrun and prevent the armature from turning, but it's possible the drive locked up and began spinning the armature several times engine speed. That will throw the windings out of the armature and lock it up, as well as creating a dead short. Remove the starter and dismantle and inspect it, or take it to a rebuilder. I'm going to bet it's trashed!
Jerry
Last edited by Hotrod Lincoln; 05/05/2010 3:23 PM.