Non-ethanol won't keep the carbs from getting gummed up if you let the bike sit too long, it just burns better and doesn't form beads of ethanol. Nothing to do with the octane.
Octane is a measure of how much energy is required to start the fuel burning. It's also an indication of how much energy will be released from burning the fuel. Higher octane fuel won't pre-detonate as easily from compression (which adds energy to the fuel) but when it does light off it releases more energy. In a Kat engine there isn't enough compression to start 87 octane burning; you still need a spark. Higher octane isn't going to pre-detonate either. The burn won't start until the spark plug fires. Then, even though it's producing more total energy from the complete burn, it burns slower so it'll still be burning when the exhaust valves open, stopping the engine from benefiting from any further burning of the fuel. In total, you get about the same amount of energy transferred to the crankshaft and the rest of the energy release goes to heating up the exhaust.
Octane is a measure of how much energy is required to start the fuel burning. It's also an indication of how much energy will be released from burning the fuel. Higher octane fuel won't pre-detonate as easily from compression (which adds energy to the fuel) but when it does light off it releases more energy. In a Kat engine there isn't enough compression to start 87 octane burning; you still need a spark. Higher octane isn't going to pre-detonate either. The burn won't start until the spark plug fires. Then, even though it's producing more total energy from the complete burn, it burns slower so it'll still be burning when the exhaust valves open, stopping the engine from benefiting from any further burning of the fuel. In total, you get about the same amount of energy transferred to the crankshaft and the rest of the energy release goes to heating up the exhaust.
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