I've heard different viewpoints on the gas too. One theory says to run a tank of premium every so often because it has better cleaning additives. The manual says to use 89 so that's what I fill up with 95% of the time.
Maybe I'm being paranoid about this carbon buildup, but I haven't seen too many pics of these 790cc twin teardowns. Out of the 4 or 5 I have seen, the two I posted I wasn't happy to see.
FWIW, the bike in the first pics is from a guy that lives in Phoenix, Az. Now the only thing that might be different about that area of the country is the gas. During the winter months they run oxygenated and ethanol additives that promotes a cleaner burn to improve air quality out here.
