Today I decided it was time to change the diff fluids. Since I bought the bike used I really had no idea when they were changed last. Front one, the fluid was pretty milky and low, to be expected, I wasnt surprised. The rear one - I pulled the drain plug, and about 3 gallons of dirty water rushed out, then some really nasty looking oil, very thick, and black. So i flushed the diff with carb cleaner, used a whole can, flushed some gear oil through it. Then filled it up. What amazes me is how well the thing ran with that nasty mix of fluids, hopefully i havent jinxed myself, just an interesting story I thought I would share.