I think this has been covered before but could find the tread. My Oil glass window is no longer transparent but has a dirty sludge on the inside see picture. The oil that came out in the last oil change was fine and new put in and yet the window is still near to useless for checking levels. So questions should I be concerned, and is there are simple solution to clear the window without taking of this side cover ?
That's condensation. Take the bike for a long enough ride or in warm enough weather and it will boil off. A hair dryer or heat gun on low may even do it. The plastic window doesn't get as hot as the metal case. It seems to be a bigger problem on the Glee than the Wee, probably because of the different oil cooling method.