What is the oil capacity of a 1990 KAW Ninja 600r?

I think its 2.5 liters, but I sold the bike in '91 or '92 after 7500 miles (laid her down). I also think the rating for cali desert was 20w/50. You can get a general idea by slowly adding oil & watching the window, try the 2.5 & see what happens. Just got an '07 & this girl takes four something liters, but she also doesn't require the oil change as quick as my old one. Good luck, hope this helps. You can also probably find a manual on eBay or info from an enthusiast site. Kinda miss the old girl, the new lady's almost as quick as a liter bike.