Hi there. I recently purchased a 2012 RMK 600 from a guy in Nevada who's been running 87 ethanol-free fuel in it from the beginning. Unfortunatly I live in the land of ethanol fuel here in CA. Should I keep running 87 in the machine or bump up to 91 since I'll mostly be filling up in CA? I've been running 91 in my '13 800 but now I'm not so sure it makes much of a difference.