Purchased a brand new 700R SE first week in April of this year - put about 11 hours on it and then did my first oil change. Used a factory filter and o-rings at change time, but used Amsoil 10w-40 ATV full synthetic. No issues, no noise up until that first oil change. After the oil change, the Raptor was fine for a few hours and then it developed a type of whine in the upper rpm range, like from mid to max rpm in each gear. No other changes to the machine other than using the Amsoil. I know that's a great oil, used by a ton of motorsports peeps, but maybe I should have used Yamalube for the first few oil changes to essentially help the parts wear in nicely, and THEN switch to Amsoil full synthetic for long-term use. Maybe there's something else going on, not sure, but I have warranty until October, so it would be nice to figure it out soon as I can. I just picked up some Yamalube 10w-40 conventional oil and I'm at 19 hours with the Raptor now, so I think I will change back to the conventional Yamalube this weekend and test. Anyone else have experience with this?