It may seem like a stupid question but I'm curious about octane recommendations, I read on lower compression bikes 91 octane is not good for combustion. I filled the tank with 91 and noticed it seems sluggish. Currently the third owner of the bike and the gentleman before me took it out maybe a hand full of times during the summer. I'm curious if it needs a carb tune or if 91 just is not the way to go. Just curious what octane is recommended.