For various reasons, I would like to begin using non-ethanol fuel (pure gas) in my 2012 YZ450. In my area of Georgia the highest octane pure gas has a rating of 90. The manual calls for a minimum of 91 octane. Does anyone have real world experience (as in you have use 90 octane "pure gas") with using 90 octane non-ethanol fuel from the pump in a late model, fuel injected YZ 450? I understand the relationship of octane requirement to compression ratio and timing curves but the comparison of ethanol 91 octane and non-ethanol 90 octane is not exactly an apples to apples comparison. It would appear that the difference between 90 and 91 octane is small. Those of you that have used 90 octane "pure gas", did you experience any pinging or detonation that you didn't experience with 91 octane ethanol fuel?