The oil that I use is somewhat transparent and you can see if there is anything suspended in it. Whenever I change the oil it looks as if there are millions of miniscule pieces of aluminum suspended in it. The engine performs well, and it seems to be in top notch shape. I do much more than the required amount of maintenance. I have 146 miles on the bike and it has had five oil changes, and the same amount of air filter cleanings. I don't neglect the bike, so whatever it is has me baffled. Any ideas?