Dave...spot on, seemingly slightly higher octane is not going to reap more power out of a 2 stroke on it's own, it may prevent some detonation if you're running too close to the edge but you'd be better off running richer rather than depending on the quality of the pump gas at any one station.
Clearly careful setting up of a bike with any higher ron fuel will give more power but if you've set up properly with 95 ron then 97, 99, 105 ron will do nothing.
http://www.nsr250.net/forums/viewtopic.php?t=310
http://www.nsr250.net/forums/viewtopic.php?t=854
I used to always buy 97 ron after I got my '28 back from Apex purely out of detonation fear, then on the eve of the 2nd dyno day Andy, Steve, Bill and myself went for a spin, it was a nice cool evening and the garage we went to sold 95 ron only. I then spent a good hour with plenty of WOT in 6th action chasing Steve and Andy over the moors will Bill occasionally zipping past at a pace only ram air assisted 16/38 geared NSR250s with 8 stone riders on can manage. I've never worried about it since.
And as mentioned plug chops are hard to read on 97 ron.
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