Yama's trying to fix this innactive clockwork. I can only see one of them. Entrprising wizards on tehir last quest will hail Yama and say "I am ready" then the quest is rather broken.
See, he pops out; just up and dissappears. Now there's an inactive clockwork about 2 steps away, but if you wait for a cue you won't hear one. Instead you'll hear the fail message "I can't believe he sent me this flunkie..". If you shock it randomly then he dies. When Yama dies he appears to be standing there again, but youcan't hail him. If you zone then he's gone. Re: spawn time, he was back the next night at least.
The gnome Yama Twerik will often be found standing over this clockwork, and I heard him say this:
Yama Twerik ponders aloud, "If only I had a flizzer valve, a spindle cog, and a spool of tin-plated wire, I might be able to make this thing work. I don't imagine that I've got any of that around here."