Hello all, i have a mower with a 15hp Kawasaki, the owner's manual says 60oz is the capacity for oil. When i drain, replace filter, and refill 60oz sometimes it will be overfilled. Are you supposed to allow for an ounce or two that simply didn't drain out of the engine? Also, when changing the oil and not replacing the filter, how much oil should be refilled into the engine. Thanks for any help.