If not then, it you just slide it back in. I might caught on the mag follower or the bolt stop/ejector.
If the bolt is decocked try to recock it like this (fyi, I used the edge of a 2x4 when I did mine): http://www.youtube.com/watch?v=CRL-RmoGdwM
lucky you for having a yugo i should have got on the wagon and bought one when they where cheap.... i did this by accident once on my turkish it take some doing out of the weapon then again when i replaced the spring mine was way to weak