its right around 1/2 to 3/4 quart i do believe i was also told by yamaha that its .70mill i think but who knows with those guys right..there is another thread in here somewhere that says if u look around in here
its .74 quarts- or 3/4 of a quart, you should have a level gauge on the bottom side by the kick starter, make sure your sitting level and fill it till that guage is covered. you may need to clean it off, its just a small circular window, but thats what its there for, or just add 3/4 of a quart. i run full synthetic 10-30 but whatever motor oil you choose works fine. happy riding