Change fuel. Why this?





#1
I was running my 08 busa with 93 pump gas and was great i decide to change to 87 pump gas and then the bike wasnt auto shifting.I have an MPS air shifter with a Boost by Smith auto shift control unit and i had to lower a 100 revs to the auto shift unit so the bike started shifting again.WHY THIS HAPPEND?
 

BA BUSA

MotoGP Wannabe
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#4
I was running my 08 busa with 93 pump gas and was great i decide to change to 87 pump gas and then the bike wasnt auto shifting.I have an MPS air shifter with a Boost by Smith auto shift control unit and i had to lower a 100 revs to the auto shift unit so the bike started shifting again.WHY THIS HAPPEND?
Why are you using 87 ???

Gen1 runs on 87...NOT a Gen2 :banghead:
 
#5
Im Form Puerto Rico and here there is only 93 and 87.And by the way is shell and with 87 the bikes runs harder.Did with 87 revs faster and thats why i had to lower the revs.
 

luvmybusa

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#6
I'm no expert but my guess would be the downgrade in quality of fuel. Owners manual specifically says the bike is designed for 90+ octane fuel. Go back to expensive stuff:thumbsup:
 

Wag

Evil Demon Busa Rider
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#7
Octane ratings have nothing to do with fuel quality. 87 octane is not lower quality gas than 91 octane or 93 octane or 105 octane. Octane ratings are only a measure of how the gas burns in the combustion chamber. Indeed, your combustion chamber's function determines what octane your gas should be!

You should use the gas that is meant for your bike. Or, another way to say it is, your bike was built for a specific gas so use that gas, not something else. It's like saying, Use the right size oil filter on your bike.

So, all Gen I Busas run on 87 octane gas and don't do well on 91 octane.

Gen II Busas run on 91 Octane gas and don't do well on 87 octane.

Assuming they're stock bikes, of course! :D

Is 93 octane okay for a Gen II Busa? Someone else should be able to answer that question better than I.

If you change octane, you won't notice a complete change in performance until about the third tank of gas

--Wag--
 

NickSully

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#11
I did some research on this when I bought my truck because it called for premium fuel also. Here is what I found and I'm quoting this from a couple different sources.

"The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use"

Hope that helps a little.
 
#12
Don't forget about altitude:whistle:...Higher altitude less oxygen in the air, hence lower octane (burns better) and vice versa.
I do run 93 octane (Busa 2005) and she is tuned for that, but my altitude is 1800m above sea level.
You can’t find 87 octane in some countries anymore, so they are forced to run 91 or higher.
I tried 93 octane for 5 tanks and then 95 (V-Power) for another 5 tanks. There is not that much difference in performance or gas mileage, Based on that I just use 93.
This is one of those topics very you will have 10 different answers by asking 10 different people. My advice – test it and see what works for you. Gen1 manual says premium or higher.
 
#13
I run 87 octane in my GenII at the track because it makes more power. Besides being more likely to detonate, lower octane fuels typically burn faster and sometimes have more BTUs (depending on the fuel) In fact MR9 and MR11 are both low octane race fuels designed specifically for bikes like the GenII Hayabusa. Detonation has a lot to do with head / piston design, and cooling, and the GenII does very well even with all that compression.

Your autoshift needed more delay because you are pulling harder at redline with the lower octane fuel.

Remember, if you did everything your owners manual told you to do, you would never go over 65 mph, or wheelie, or do burnouts, or ...
 
#14
I run 87 octane in my GenII at the track because it makes more power. Besides being more likely to detonate, lower octane fuels typically burn faster and sometimes have more BTUs (depending on the fuel) In fact MR9 and MR11 are both low octane race fuels designed specifically for bikes like the GenII Hayabusa. Detonation has a lot to do with head / piston design, and cooling, and the GenII does very well even with all that compression.

Your autoshift needed more delay because you are pulling harder at redline with the lower octane fuel.

Remember, if you did everything your owners manual told you to do, you would never go over 65 mph, or wheelie, or do burnouts, or ...
Exactly,the lower the octane the more power but it also produces more heat upon detonation.
 
#15
OK guys, here is a fairly good answer from a maker of the famous banned racing additive "ExtremePower Fuel Additive". The Gen II is designed by piston, head and fuel injection A/F ratio for 91 octane minimum. This is so you will not have detonation in every climate and temp. If you use 87 octane, you are really putting the engine where it could easily detonate and cause premature wear on pistons and valves. I would never use 87 in a Gen II. Sure you can do it, the motor will not quit running, but you are putting a 12:1 compression motor at risk. For what? One tenth of a second? Two tenths? Please stick with 91 or higher 93 octane and your motor will thank you. Some bikes run faster on 93 octane and others on 87, it depends on your individual bike. Stick with the 91 or higher!

I hope this helps! Clear as mud........
 

Wag

Evil Demon Busa Rider
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#16
--snip--
I tried 93 octane for 5 tanks and then 95 (V-Power) for another 5 tanks. There is not that much difference in performance or gas mileage, Based on that I just use 93.--snip--
That's exactly the right thing to do. Purging the tank of the prior tank of gas is going to take at least a couple of tanks and then the other three tanks will average out the variances in riding habits, etc. If you really want to know the effect of the gas you're using, this is the right way to do it. Average the last three of the five tanks of gas and you'll be pretty close to on the money for your purposes.

This is one of those topics very you will have 10 different answers by asking 10 different people. My advice – test it and see what works for you. Gen1 manual says premium or higher.
What you sometimes see in people's opinions is that the higher octane fuels have different detergents or they burn cleaner or any other number of other reasons to use it which have little to do with the octane. No matter what, though, for some reason, many will continually argue the "fact" that higher octane means "better" somehow. Dig into the details with them, though, and they have little knowledge or fact to back up what they're saying, nor will they go do any research on the subject.

Granted, if you go from one gas station to another, you may find some differences in quality but once again, it has nothing to do with octane!

If your vehicle is not designed for the higher octane, it is going to run less efficiently. This is something which can and has been proven. It's not a matter or opinion no matter how much people will attempt to make it so.

Oil, on the other hand, IS a matter of opinion! :laugh:

--Wag--
 

Mr Bogus

Trouble Makers Inc.
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#17
Octane is simply a fuels ability to resist burning or ignition.. the higher octane can prevent pre-ignition and detonation

Alcohol has an octane of around 110
Diesel as I recall is around 20 or so (is actually cetane)
 
#19
I run 87 octane in my GenII at the track because it makes more power. Besides being more likely to detonate, lower octane fuels typically burn faster and sometimes have more BTUs (depending on the fuel) In fact MR9 and MR11 are both low octane race fuels designed specifically for bikes like the GenII Hayabusa. Detonation has a lot to do with head / piston design, and cooling, and the GenII does very well even with all that compression.

Your autoshift needed more delay because you are pulling harder at redline with the lower octane fuel.

Remember, if you did everything your owners manual told you to do, you would never go over 65 mph, or wheelie, or do burnouts, or ...


Never knew that lower octane fuels produced more power.

Not trying to start a disagreement -
Why does NASCAR/NHRA/MotoCross/AMA all use higher octane racing fuels?
 
#20
I have a power commnader 5 with auto tune and i set it for 12.5 A/F ratio.I think that is safe to run 87 with that setting of A/F.What do you guys think or i should run other A/F setting?
Thanks for all the help!!!!
 

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