I have a 2004 raptor 660, Bought it used about with about 2 times riding on it. The guy changed the oil once, I changed it after about 5 hours of driving its been about 5-7 or so hours and I plan on changing it again. He changed it with yamalube, and so did I, I was wondering should i stick with yamalube, for a little more, or can/should I maybe go to a synthetic since I think the engine has broken in enough where it would be ok for synthetic? Any ideas or should I just use a normal motor oil. What grade should I put in it. Last time I changed it I went with a 5W30 because its been a little cold in Wisconsin lately. Should stay with that?

Thanks,

MIke.