I have seen the posts about the foggy oil sight-glass in cold weather. Now, I rode the bike (2006 620) at least 1 hour at varying highway speeds the other day. It was around 55 degrees F outside. The glass was still a little fogged, but the oil in the glass looked normal. By the time I made the return trip, 1 hour home, the glass still had a tiny spot of fog. It seems that a little condensation on the sight-glass is normal then, no matter what you do, in cold weather. Kind of like a fogged window in a house? I know one thing, I plan to ride the 620 regularly, a much a spossible, through the winter (here in Virginia).