I've been riding my XT660Z for 4 year and I think it sounded like this from the begining, but recently I helped my friend to look for a Tenere for him and two bikes we checked runned quiter.

https://drive.google.com/open?id=0B5...lIxM21ReWpOcEE

Not sure if there is something wrong with mine. Maybe someone can help. The bike is from 2008 and has 44000 km on the clock. Valve clearance done recently by a workshop.
The engine does take some oil.