Just bought a Brand New 2004 Yamaha Grizzly 660 and have been breaking it in and have 6 hours and 30 miles on it. The guys on this site told me to change the oil the 1st or 2nd day of riding. What kind of oil should I use, yamahalube? What should I do with oil filter, clean it or leave it alone? What other maintenance should I do right now?