[motoyoyo]

Gee, you wouldn't want to share the name of this BMW dealer would you? If they could screw up some thing as basic as a valve adjustment, would you really want them tearing the whole motor apart? I would at least get them to cough up the mechanic that worked on it and keep him far away from your bike. Also, keep in mind that the broken tappet screw has already become familiar with other engine parts, otherwise you never would have heard any noises in the first place.