Topic: Need some fuel advice

[crazypj]

Octane rating and burn rate are two different variables. There are high octane fuels that burn faster than 87 pump gas, and there are high octane fuels that burn slower than 87 pump gas. It is the same thing as saying that people who can lift heavy objects run slower than people who can't lift heavy objects. There are plenty of people who can out lift and out run me 

Burning up exhaust valves has to do more with the temperature of combustion rather than the length of combustion. Some fuels (especially ones with higher oxygen levels) will burn leaner than others. If the jetting is not adjusted then you will end up with a hotter combustion that will cause problems in the long run. In general you will not see anything like this simply going from 87 pump gas to 93 pump gas though, you would need to jump to a much more exotic fuel.

 I was under the impression the entire reason for octane rating was to maintain anti-knock and burn rate? (since 1915~1916?)
My first reply (post #3) says to adjust jetting as E10 fuel leans mix

[TwoTired]

Octane rating and burn rate are two different variables. There are high octane fuels that burn faster than 87 pump gas, and there are high octane fuels that burn slower than 87 pump gas. It is the same thing as saying that people who can lift heavy objects run slower than people who can't lift heavy objects. There are plenty of people who can out lift and out run me 

Burning up exhaust valves has to do more with the temperature of combustion rather than the length of combustion. Some fuels (especially ones with higher oxygen levels) will burn leaner than others. If the jetting is not adjusted then you will end up with a hotter combustion that will cause problems in the long run. In general you will not see anything like this simply going from 87 pump gas to 93 pump gas though, you would need to jump to a much more exotic fuel.

 I was under the impression the entire reason for octane rating was to maintain anti-knock and burn rate? (since 1915~1916?)
My first reply (post #3) says to adjust jetting as E10 fuel leans mix

Burn rate and ignition susceptibility are two different properties.  FYI

[KJ790]

Octane rating and burn rate are two different variables. There are high octane fuels that burn faster than 87 pump gas, and there are high octane fuels that burn slower than 87 pump gas. It is the same thing as saying that people who can lift heavy objects run slower than people who can't lift heavy objects. There are plenty of people who can out lift and out run me 

Burning up exhaust valves has to do more with the temperature of combustion rather than the length of combustion. Some fuels (especially ones with higher oxygen levels) will burn leaner than others. If the jetting is not adjusted then you will end up with a hotter combustion that will cause problems in the long run. In general you will not see anything like this simply going from 87 pump gas to 93 pump gas though, you would need to jump to a much more exotic fuel.

 I was under the impression the entire reason for octane rating was to maintain anti-knock and burn rate? (since 1915~1916?)
My first reply (post #3) says to adjust jetting as E10 fuel leans mix

Burn rate and ignition susceptibility are two different properties.  FYI

Bingo.

Octane rating is the rating of a fuel's resistance to ignite without a spark present (under heat and/or pressure alone). Burn rate is the speed at which a volume of fuel burns once ignited by spark. They are not the same and are not related to each other. Many high octane fuels are actually formulated to burn faster, as they are intended for high RPM racing applications. A fuel designed for a racing engine that runs 14:1 compression and has peak power at 13,000 RPM is going to have a higher octane rating and a faster burn rate than a fuel intended for a street car that is 8.5:1 compression and has peak power at 5,000 RPM.

However the difference between regular and premium pump gas is typically very minimal other than the octane rating, as both fuels are intended to be used in over the road street cars.

[70CB750]

Is it just me with a Déjà vu right now?  We talked gasoline two month ago at max.

[Black 750K8]

My bike will run on any pump gas. I think it is because all of those pumps are fed by one big tank under the ground.

[Stev-o]

Is fuel the new oil thread?!

I believe it is too!
I did put some 91 in the bike yesterday afternoon. Bike felt real strong when I used lots of right hand twisting.... Must be an acceleration thing...

I filled up with good smelling [up to] 10% ethenol 87 octane and the little 550 was running like a bat outta hell on the twisties!