Jeremy (mx-tech) recommends mobil-1 for interval home maintenance. I've never measured its viscosity, but it is around 5-7W depending on whom you ask.
Oil level recs vary, too. Most often you'll hear 100mm. I prefer 110.
That level is measured with the fork collapsed, spring out. If you've just changed your oil, insure there are no bubbles/voids in the fork. 'No bubbles' by letting it set for a bit, maybe some light tapping on the fork. 'No voids' by moving the rod up and down until you don't hear any air squishing.
well, from my manual the stock oil capacity is 618+/-4 ml oil level is 140+/-2 mm with spring removed and fully compressed adj. range is from 110-170 mm i m sure if you look at the search part of this site there are many threads on fork oil, type quantity ,methods ,springs ect. hope this helps ps get a manual either factory or clymer you need one to work on your bike.!!!!!!
I was using 7.5W oil (5 + 10 combined) which was fine for the trails until I started riding MX and found it was letting the front wheel rebound back up into the air after landing from jumps so I changed to 10W (as Kaw recommends) and that took care of that problem.