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Discussion Starter #1
Hi all.

I have an Ultra Classic, EFI with 95" kit. The HD manual says to use any fuel 87 octane or better.

With 87 or even 89 octane I get rattling in the engine (don't know the technical term) when accelerating uphill. 91 octane seems to work ok but every now and again it makes a bit of the same noise. With the 94 octane there is no rattle.

I'm wondering if this is typical or if there is some adjustment for lower octane fuel? I'm thinking not, being EFI.

What octane do you all use?

Thanks.
 

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Ultra RB said:
Hi all.

I have an Ultra Classic, EFI with 95" kit. The HD manual says to use any fuel 87 octane or better.

With 87 or even 89 octane I get rattling in the engine (don't know the technical term) when accelerating uphill. 91 octane seems to work ok but every now and again it makes a bit of the same noise. With the 94 octane there is no rattle.

I'm wondering if this is typical or if there is some adjustment for lower octane fuel? I'm thinking not, being EFI.

What octane do you all use?

Thanks.
Your compresion is probably higher now,. you need to run 91 or better. My 05 RK recommends 91 or better also.
 

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omahacd said:
I always run premium in my 02 rkc.
The HD website lists this for the 04 Ultra under "specs":
3) Recommended 91 octane or higher fuel (R+M)/2.
I always run 92-93 octane in my 02 FLHRCI no problems with pinging
 

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Which manual says to use 87 octane or better? The owner's manual for my 99 says to use 91 octane or better. Every manual I've seen for TC's says the same thing. Is something different north of the border?

If you only have the HD reflash for your 95" setup, you most likely need some help with the EFI system to control pinging, ie, PC or other device. Lots of info on the board about options.
 

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I like Sunoco Ultra 94 octane. But I vary between the higher end gas stations.
Amoco, Sunoco, Mobil, aways using premium. I stay away from the lower end cheapie stuff.
Sparky
 

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Discussion Starter #8
87 octane manual ...

Ed and Rick ...

Official Factory Manual "1999 Harley-Dav Service Manual", page 1-9, (Fuel)

"Use a good quality leaded or unleaded gasoline (87 pump octane or higher)."

But in my '99 owners manual it does say 91 as does yours ...

Interesting that they differ.

Bottom line is that it runs best on 94 octane. I proved that again tonight when I went for a good ride ... had 91 octane in it on the way out and had some pinging, filled up with 94 and no pinging on the way home.
 

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sparky88 said:
I like Sunoco Ultra 94 octane. But I vary between the higher end gas stations.
Amoco, Sunoco, Mobil, aways using premium. I stay away from the lower end cheapie stuff.
Sparky
I have used the Ultra 94 and it is no better than the 92's & 93's out there. The bike runs no differently. I think we are just waisting another 8-10 cents a gal by buying the 94.
 

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Ultra RB said:
Ed and Rick ...

Official Factory Manual "1999 Harley-Dav Service Manual", page 1-9, (Fuel)

"Use a good quality leaded or unleaded gasoline (87 pump octane or higher)."

But in my '99 owners manual it does say 91 as does yours ...

Interesting that they differ.

Bottom line is that it runs best on 94 octane. I proved that again tonight when I went for a good ride ... had 91 octane in it on the way out and had some pinging, filled up with 94 and no pinging on the way home.
You're right about the HD service manual. Just went and checked mine and it says the same thing. I suspect that it is a left over from previous years with the Evo engine. Maybe someone with a 2000 or later service manual will check and see what it says.

I do run 89 octane in mine in cold weather months. No problems at all. I also ran 89 octane last month in places while on the way to Sturgis (rural Nebraska). Anything higher was not to be found. Didn't have any problems then either.

What cams are you using? How about ignition? Either or both would make a difference.
 

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doesn't matter..

Well, if you are fueling at a "new" station, it will take 2.5 gallons to flush the previous purchase from the hose anyway. So buy the cheap stuff and add some Octane booster. If you are buying less than 2 gallons, it's most likely you are still getting the "previous" purchase. If your regular station has a hose for each flavor then you get all the fuel you pay for....

So, to be on the safe side I add the OCTANE booster every chance I can when I'm forced to buy from a "single hose" pump. Just the way it is..
 

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sparky88 said:
I like Sunoco Ultra 94 octane. But I vary between the higher end gas stations.
Amoco, Sunoco, Mobil, aways using premium. I stay away from the lower end cheapie stuff.
Sparky

Ironicly, when I used to work at a Conaco station, the delivery truck filled our tanks and the station across the street, a Texaco station. My dad used to work at Sinclair station, and the same truck delivered fuel to a Amoco station down the street. All 4 of these stations bought thier fuel from the same distributer in Aberdeen SD. Just different delivery trucks. I am pretty sure that the distributer doesn't have 4 different tanks for 4 different brands, and I am also pretty sure that the trucks don't have enought seperate tanks to hold 4 grades of fuels for each brand. I don't think brands really matter that much.
and funny enought, people would say things like, "I would never buy fuel from that texaco station".... If they only knew.

I can't speak for major cities, they might actually have different distributers with different fuel.

tom
 

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tbiker99 said:
Ironicly, when I used to work at a Conaco station, the delivery truck filled our tanks and the station across the street, a Texaco station. My dad used to work at Sinclair station, and the same truck delivered fuel to a Amoco station down the street. All 4 of these stations bought thier fuel from the same distributer in Aberdeen SD. Just different delivery trucks. I am pretty sure that the distributer doesn't have 4 different tanks for 4 different brands, and I am also pretty sure that the trucks don't have enought seperate tanks to hold 4 grades of fuels for each brand. I don't think brands really matter that much.
and funny enought, people would say things like, "I would never buy fuel from that texaco station".... If they only knew.

I can't speak for major cities, they might actually have different distributers with different fuel.

tom
Had a relative that managed a fuel depot in Macon, Ga. He said all tanker trucks were filled with exactly the same fuel no matter what brand was on the side of the tanker.
 

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cfell said:
Well, if you are fueling at a "new" station, it will take 2.5 gallons to flush the previous purchase from the hose anyway. So buy the cheap stuff and add some Octane booster. If you are buying less than 2 gallons, it's most likely you are still getting the "previous" purchase. If your regular station has a hose for each flavor then you get all the fuel you pay for....

So, to be on the safe side I add the OCTANE booster every chance I can when I'm forced to buy from a "single hose" pump. Just the way it is..
Very interesting cfell. I thought there for a minute you was full of bs.
Then I did the math--a 2" id x 15' long hose will hold about 2 1/2 gal.
Of course it's unlikely that the whole dam hose would be full of gas but I'm sure there is a little bit more somewhere else in the system.
Very interesting indeed
 
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