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Discussion Starter #4
what exactly is knock or ping?
I hope that this answers your question.

There is a lot of confusion about what the "octane number" on the gas pump means, what higher octane numbers really mean, and why some engines need or can take advantage of a higher octane fuel.


In a nutshell, the octane rating of a fuel is a measure of its ability to resist detonation, ping, pre-ignition, or knock. Although purists will quibble, all of these terms can be described as an incorrectly-timed burning of the fuel/air mixture in the combustion chamber. Any motor fuel will spontaneously ignite under the right conditions - too much compression, hot spots from leftover carbon deposits, excessive boost, too much ignition advance, or a number of other causes can provide the source of ignition.

When the flame front from this ignition event meets the one created by the spark plug, the result is sky-high cylinder pressures and a destructive shock wave that can shatter spark plug insulators, hammer rod bearings, break rings, or even put a hole in the piston. The octane number is a way to express the resistance of a fuel to this type of unwanted ignition.
 

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Good info. I have always used high octane in my bike though. The biggest piece of information that got is..."Almost all of today’s new cars have FUEL-INJECTED engines that need to use gasoline with a detergent additive. They do not necessarily need high octane gasoline with a detergent additive." I know I don't have fuel-injection in my bike, so I don't know if that makes any difference. I'm interested in any feedback about the difference.
 

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something to take into consideration is if you are riding an air cooled motor, like most v-twins, they have a tendency to run hotter than water cooled motors, and the lower octane rated fuels will want to pre detonate sooner which will cause poor performance and a ping sound, which is the knock, if you ride in hotter conditions, use the high octane fuels even if you bike calls for the low stuff, you won't necessarily have to do this all the time but the occasion does arrise.

you roadliner, strato, raider, riders it is a must
 

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Good info. I have always used high octane in my bike though. The biggest piece of information that got is..."Almost all of today’s new cars have FUEL-INJECTED engines that need to use gasoline with a detergent additive. They do not necessarily need high octane gasoline with a detergent additive." I know I don't have fuel-injection in my bike, so I don't know if that makes any difference. I'm interested in any feedback about the difference.
without f/inj, it is more important to find the right fuel for your bike. If you are running a touch lean, or ride a lot at high (5-8k) altitudes, you would find that a premium fuel might be better. If you are a touch rich then a faster burning gas would be to your advantage.
Play with grades and find what is right for your bike, not "what everyone else is doing"
Or, trade up to Fuel/inj and let the computer do the work for you.
 
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