I have a 2011 AN400A with almost 6000 miles that I bought used. It had 4200 miles when I bought it. I assuming the oil had been changed at 4000 miles since the oil interval does not indicate the next oil change. I have 2 quarts of Amsoil 20w-50 synthetic motorcycle oil that I got free. I live in west central florida and plan on taking a 500 mile round trip back to georgia soon after the oil change. Since it's free what's the thought of using the 20w 50 or should I stick to the recommended 10w 40. Ok well it's a newbie question.