in my search for 660 information i've found a site with a free download of the tenere xtz660 manual.
its got alot of useful info for the home mechanic, the more in-depth stuff that many manuals miss.
some sort of copywrite will exist so i must say under no circumstances should you download this if you have a 660 engined thumper, and as such it must not be found useful or interesting.
don't go here;
www.staddle.net/dokuwiki/motorcycles/xtz660/manualbullet350