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I know that the owners says to use regular gas, but what do you guys and gals use for your bikes? And, how about your milage? After installing devils, my milage decreased.
 

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Yeah it's fast...
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at the risk of sounding like an asshole...use the search feature, these topics have beem discussed numerous times in this forum.
 

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Rough Crowd :)
:ar :spank
 

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The guys are correct but I'll answer the question. I use premium gas (92) simply because of the high compression ratios. That's really all that matters. The higher the octane levels, the higher the flash point of the gas. The higher the compression ratios, the hotter the air fuel mixture gets in the cylinder before the spark (universal gas law; PV=nRT). As long as you don't hear any knock, then that's all that matters. If yamaha says 87, then I would assume they tested it and they know. I'm an engineer for a large company in the heavy equipment industry and I know that's how we do it.
 

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I just recently dropped down from super to regular.
Since changing my exhaust cans, I noticed a lot of popping and backfiring when backing off the throttle..

Someone here suggested using the 86/87 octane (whatever the manual recommeded) and it has significantly decreased the amout of popping/backfiring although it did not get rid of it completely...

Plus it saves a few bucks each fill up with the way gas prices are these days.
 

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Respect My Authority!
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87 octane unless I get knocking or pinging which I don't. Save your money wherever you can.
 

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Hippie said:
Rough Crowd :)
:ar :spank
It's not so much a rough crowd as it is the frustration when the same subject is beat to death. Granted most newbies don't know about the search feature, so it's pointed out as nicely as possible.
 

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04Fizzer said:
It's not so much a rough crowd as it is the frustration when the same subject is beat to death. Granted most newbies don't know about the search feature, so it's pointed out as nicely as possible.


I know.. I was only joking...

I think the thing is, that there are SO MANY different threads here even using the search button can be overwhelming to find the simple answer you want...

At least for me it used to be (and still is some of the time)

Sometimes it is a lot less of a headache to just ask again...

Also, maybe they should make the search button b***** and easier to find?.. (just a thought)

Anyhow..
Pawel: I feel your pain.. :)
Did you get your answer to the octane question you originally posted?
 

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maybe we could sticky the REALLY common threads, like octane, the exhaust thread, etc... I know they are under "topics worth linking" but when I was a n00b I didn't even see that.

Or better yet, where's that FAQ Pretender was working on? :D :banana
 

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Gand said:
I know they are under "topics worth linking" but when I was a n00b I didn't even see that.
??? Did I miss something?
 

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The dealer told me to use premium so that what i use. I do get a quite a few of back firing or pops when i get off the throttle in the higher rpm's. Im not sure if it hurts anything, but im a newbie when it comes to mechanics etc.
 

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jbright44 said:
I use premium gas (92) simply because of the high compression ratios. That's really all that matters. The higher the octane levels, the higher the flash point of the gas.
But didn't Yamaha de-tune the bike's compression lower then a R6's motor. I know the R6s have to use super, and it even says it in the manual but on ours it says 87. Lower compression, lower octane? I seemed to have gotten better gas mileage (not much) on regular vs. super.
 

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jbright44 said:
The guys are correct but I'll answer the question. I use premium gas (92) simply because of the high compression ratios. That's really all that matters. The higher the octane levels, the higher the flash point of the gas. The higher the compression ratios, the hotter the air fuel mixture gets in the cylinder before the spark (universal gas law; PV=nRT). As long as you don't hear any knock, then that's all that matters. If yamaha says 87, then I would assume they tested it and they know. I'm an engineer for a large company in the heavy equipment industry and I know that's how we do it.

Premium fuel burns cooler, less BTU however, using regular will have a significant effect on performance in timed tests. Also, if you are riding in an area that has temperatures above 95 degrees ambient, the engine will run hotter and the chances of pinging are far greater. Also is the fact that you may not hear the engine ping above the standard noise level. At 2.539 the difference per tank for me is a mere 80 cents. I'm not going to bother even thinking about switching for 80 cents. It's not worth it........

Hawk
 

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Stephen Hawk said:
Premium fuel burns cooler, less BTU however, using regular will have a significant effect on performance in timed tests. Also, if you are riding in an area that has temperatures above 95 degrees ambient, the engine will run hotter and the chances of pinging are far greater. Also is the fact that you may not hear the engine ping above the standard noise level. At 2.539 the difference per tank for me is a mere 80 cents. I'm not going to bother even thinking about switching for 80 cents. It's not worth it........

Hawk


exactly my thoughts, plus I live in Phoenix, AZ where not only does it get hot in summer but they use oxyginated fuel in the summer as well.
 

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Question: Will the type of gas being used (regular vs. premium) have an effect on the results of a bike being dyno'ed?
 
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