excessive timing chain slack

[danshaz82]

i finally got the car running right, and tonight i noticed that there was an obnoxiously loud scratching noise from the front of the head. sounded like the chain was hitting something. i took the VC off and turned the motor over by hand to see. i noticed the chain would go from very tight, to super loose.
[youtube]http://www.youtube.com/watch?v=dsI5igQ2 ... r_embedded[/youtube]
figured it was a bad tensioner. took off the front cover to check, and the tensioner looks brand new.
another video, this time with the cover off. watch it full screen in hd so its easier to see.
[youtube]http://www.youtube.com/watch?v=xaABDnef ... r_embedded[/youtube]
this doesnt seem right.
any ideas?

[danshaz82]

figured out that the threads for the idler sprocket stripped. a mod can lock this thread if theyd like.