The stock bike uses ~ 4 quarts total for tank and filter.
You should run at least that amount total. More than that is okay. I wouldn't be comfortable running less than that amount.
Drain all; tank, filter, engine.
Fill with there quarts oil. Run engine and note sight gauge level. This is the quart low level.
Add another quart. This is your full level, unless you decide to run with larger capacity. Adjust level to suit.
Cheers,