And there was me thinking I posted a similar sort of question, and there's my thread.

I did what Dave suggested, but only for 200 miles (the office and back) and it was a surprise the black colour of oil that came out. Although the current stuff still looks nice and clean.

I once had a KLR 650 and the oil sight glass had misted over through running poor oil for extended times, when I got it I changed the oil to a good quality synthetic went on a couple of good runs and noticed that the sight glass had started to clear, after a couple of hundred miles it was almost back to normal.

There you go just read the link Guido put up.