Originally Posted by sleepywombat
theres a 2nd airfilter ?
I reckon Davo's referring to the CV Carb breather which used to come poorly equiped from the factory (probably still does?). I didn't know about it on my first DR and as a result the carb slide got dusted and scored. After that I used some fine air filter type foam in the breather and gave it an oil with filter oil every now and then to be sure.
I imagine it would only be an issue for riders who encounter a lot of dust.