Somebody PM'd me the following:
I cant tell where the oil level is in the window it looks the same all across. so either its very empty or overfilled.
The first thing to do is put the bike on the side stand. You should see either no oil in the sight glass window or maybe just a little at the bottom. It should look about like this - but without all of the bird guts on the side of your bike. :yes
Oil sight glass windows can:
a) become very crazed so that its hard to see the oil level (sometimes using a good bright flashlight can help you see through a hazy sight glass)
b) become very dark so that, again, it's very hard to see through them
If you determine a) or b) is the case then its time to install a new one.
If you're not sure how much oil is in your bike (over-filled or under-filled) then drain the oil
and change the filter. Watch the oil sight glass window as it drains to see if you can see the oil level going down. If you can then you probably had too much oil in the bike.
After you've changed the filter and buttoned things back up, add about three quarts of oil. Slowly add another 2/3 of a quart while watching the sight glass window. If you don't see the oil level rising as you add oil then you need probably need to install a new sight glass window.
After you've refilled it remember to run the bike for a minute or two to fill up the oil filter, then turn it off and let it sit for ten minutes and then check the oil level again.
