Question about Bike's Year and Fuel used

[SFCMcGan]

Absolutely! The Octane debate always shows up on forums... Octane numbers relate to the amount of compression an engine has... Octane ONLY prevents detonation (the point where the fuel ignites itself rather than from the spark plug) 87 octane is good for all engines up to aroud 10.5:1 compression (I will look for the article to reinforce these numbers) after that... you will get detonation under a load. then you need to bump up to 89 octane... to caveat Sean's information... this is under normal conditions... you start hammering on the rpm's, then you might want to bump up the Octane to help prevent detonation from the combination of heat, timing and pressure. Octane does not increase power, or makes your engine run cooler in any way... it only prevents detonation....

So based on what I am reading, I have a question. Would higher octane fuel contribute to a Rich condition and Plug fouling?:ummm:

Nope... once a spark is introduced to the compressed fuel... it burns... Higher octane fuel by itself does not increase power whatsoever... when fuels is compressed... it begins to get hot... in higher compression situations... to the point of self ignition. Octane "additives" (which is not really an additive it is processing) merely raise the "boiling" point of the fuel.

Diesels work on the "detonation" principle.... squeeze the hell out of the fuel until it self ignites (sometimes as high as 20:1 compression)... ahhh... but what about glow plugs.... they are only used when the engine is cold and the pistons are not producing the needed compression initially... glowplugs are not used at all after the engine is started.

 

[Miles Long]

Thanks to all that have helped to debunk the myth of higher octane = better performance.
I have met several bikers that will not use anything but premium gas -"high test"- regardless of what they are riding, and or compression ratio of their engine. Most reason that the bike "works better", but a few use it because most brands of high-test, at least in this area, do not contain the dreaded ethanol additive. Anyone know the reason for this? No doubt related to the detonation point?
Cheers!

 

[AMechEng]

They manufacturer will post the fuel the bike needs under the harshest conditions. Meaning the hottest it will get and under the heaviest throttle loads. The higher the octane fuel the harder to ignite and the slower it burns. You want to run the lowest octane you can get without detonation. This makes the most power (and efficiency).

Even 1428 and 1500 engines will run fine on 87. Long rod or high compression engines should consider the 91 as the standard fuel unless the tank of fuel they will be running is used for normal driving around. The demands on the fuel will be far less and even octane of a much lower rating would work.

The gen 2's will also run on standard 87 fuel with no problems. (detonation). But, if you're going to be racing it or in conditions that will get it at the hottest levels AND racing it then you for sure want the higher octane fuel. Even the reflash takes advantage of advancing the timing curves to put more strain on the fuel so the 91/93 fuel will work better in those conditions. BUT, still - for normal riding even with that flash work the 87 will still work just fine (and run cleaner with better economy).

So what do I have to do to reflash my '86? Everyone tells me I'm abusing my bike running 87 so I figure if I reflash it I can run 93. LOL

Serious question: if you take pure 87 octane gasoline and add 10% ethanol then the octane rating will be higher since alcohol is somewhere around 120 octane I think. So do you think the refiners adding 10% ethanol is just a scam so that they can use more of the barrel of oil in the refining process and hit their octane levels?

 

[dannymax]

So what do I have to do to reflash my '86? Everyone tells me I'm abusing my bike running 87 so I figure if I reflash it I can run 93. LOL

Serious question: if you take pure 87 octane gasoline and add 10% ethanol then the octane rating will be higher since alcohol is somewhere around 120 octane I think. So do you think the refiners adding 10% ethanol is just a scam so that they can use more of the barrel of oil in the refining process and hit their octane levels?

That's an interesting theory, quite possible too, I bet! unk:

 

[SFCMcGan]

Here is some good reading... Lots of facts... look at the very last paragraph about motorcycles....... Keep in mind... with only very few exceptions... ALL main stream gas stations have ethanol blended fuels in Regular, mid and premium gas...

http://www.ethanolrfa.org/pages/ethanol-facts-engine-performance

 

[DMAN999]

So what do I have to do to reflash my '86? Everyone tells me I'm abusing my bike running 87 so I figure if I reflash it I can run 93. LOL

Serious question: if you take pure 87 octane gasoline and add 10% ethanol then the octane rating will be higher since alcohol is somewhere around 120 octane I think. So do you think the refiners adding 10% ethanol is just a scam so that they can use more of the barrel of oil in the refining process and hit their octane levels?

Your motorcycle was designed to run 87 octane, so you are NOT abusing it at all.
Read the owners manual, it clearly says to use 87 Octane and ONLY use higher Octane fuel if your motor is pinging.
And I'd guess that the 87 on the pump is calculated with the ethanol already in it.

PS
We can't re-flash our Gen 1, they aren't Fuel Injected.

 

[srk468]

I don't subscribe to the line of thought that more octane will cost horsepower, there isn't any gain either but too much octane won't cost horsepower except in extreme examples such as running C16 in a stock Vmax. I just raced last weekend and my et and mph were identical using pump 92 octane and 110 octane racing fuel. I wanted to test that theory so I made a motor pass on race gas and it was the same but I usually only run race gas when I'm using nitrous.

sent from my HTC Rezound using tapatalk

 

[AMechEng]

Your motorcycle was designed to run 87 octane, so you are NOT abusing it at all.
Read the owners manual, it clearly says to use 87 Octane and ONLY use higher Octane fuel if your motor is pinging.
And I'd guess that the 87 on the pump is calculated with the ethanol already in it.

PS
We can't re-flash our Gen 1, they aren't Fuel Injected.

Don't tell me what I can reflash. I'll reflash what ever the fuck I want.:rofl_200:

 

[dannymax]

Don't tell me what I can reflash. I'll reflash what ever the fuck I want.:rofl_200:

And here's just the tool to do it with!! :rofl_200:

Click Here

 

[AMechEng]

Here's some matches and some 93 octane. Time to reflash your bike.

 

[mr.maxx]

my old maxim x seemed to run better with 89... that's the only bike i ever noticed any difference. and ive had many bikes