Octane? Really?
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Ultimate HDF Member
Joined: Sep 2007
Posts: 8,831
Likes: 15
From: Nomad
Run the lowest octane that your motor will tolerate. If you are not accellerating hard and don't lug the motor 87 octane will do fine. It fires easier and gives more mpg.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
I was wondering if going up in octane could have thrown the ECU off so much that I got that rough idle and stalling.
Bad gas makes more sense, though. The place is call Kum-n-Go, after all.
Stellar HDF Member
Joined: Aug 2007
Posts: 3,159
Likes: 1,079
From: Brandon, Mississippi
Eggzactly!
Run the lowest octane that your motor will tolerate. If you are not accellerating hard and don't lug the motor 87 octane will do fine. It fires easier and gives more mpg.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
Tourer
Joined: May 2010
Posts: 257
Likes: 0
Run the lowest octane that your motor will tolerate. If you are not accellerating hard and don't lug the motor 87 octane will do fine. It fires easier and gives more mpg.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
the higher power comes from the higher compression. The same amount air and gas compressed into a smaller area and then ignited will yield higher energy.
Seasoned HDF Member
Joined: Jul 2007
Posts: 6,336
Likes: 67
From: SW Minnesota
Run the lowest octane that your motor will tolerate. If you are not accellerating hard and don't lug the motor 87 octane will do fine. It fires easier and gives more mpg.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
Many confuse octane with power. The octane rating is only to indicate the resistance to igniting and all octanes yield the same power.
Run what your manual tells you, which is a minimum of 91 octane.
Tourer
Joined: May 2010
Posts: 426
Likes: 0
From: Tucson, AZ
I always run 91 octane. Not sure if it matters or not but the price difference for such a small amount, I just figure "what the heck, why not?". I used to try and fill up at a "premium" station but in the last several years I just fill up anywhere.
Outstanding HDF Member
Joined: May 2007
Posts: 2,921
Likes: 199
From: Skunk Hollow, TX
Gotta disagree with your first paragraph. Whether or not your bike seems to run fine is totally dependent on the engine management system adjusting for detonation. As soon as the knock sensors detect detonation, your spark will be retarded to prevent detonation. If you are not running at full advance, you are losing power and gas mileage. There is only so much it can do, however, and if it's already retarded your spark due to the low octane, and you get into a lugging or high heat situation, you may have used up your engine's ability to compensate, and detonation will occur.
Run what your manual tells you, which is a minimum of 91 octane.
Run what your manual tells you, which is a minimum of 91 octane.
Extreme HDF Member
Joined: Mar 2008
Posts: 14,865
Likes: 4
From: Mn.on a lake,well nxt to a lake.
I run 89 in both bikes(01 is carbed and 06 FI) with no problems so I dont see a need to change.....Even new cars/pickups recomend 87 due to the ECM's,heck even new boat motors recomend 87 oct.....
Intermediate
Joined: Jan 2010
Posts: 41
Likes: 0
From: buena park, ca
maybe a dumb question but is your bike carburated and are you still at low alltitude?
all gas is the same, only the additive is different.
all gas is the same, only the additive is different.
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Road Captain
Joined: Jul 2009
Posts: 599
Likes: 2
From: Montana
What % of the gas was Ethenol? That stuff attracts water and if its an old batch that was in their ground tanks for awhile, it probably sucked some up. With all the rain (and snow!) that you have had lately, that could be the problem.
Road Captain
Joined: Jan 2009
Posts: 566
Likes: 7
From: Seattle, WA
On a hot day or with a heavy load EFI will pull back and you won't be getting rated power from your engine. It will run OK and it will not suffer damage, but do realise that the engine won't be making full power.