Which Fuel?

Discussion in 'Sportster Models' started by iron_ty, Aug 9, 2011.

  1. iron_ty

    iron_ty Member

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    I've been burning premium gas (92 octane) in the 883.. is this really necessary? will it run just as well on regular? (87 octane) would be a lot cheaper to just run regular...
     
  2. wilks3

    wilks3 Junior Member

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    How much cheaper? What does your manual call for? Less octane, factory ECM will take timing away, bike won't run as good.
    Look at it this way, "if" you put in 10 gal a week, and it cost 20 cents more a gallon, thats $2.00 more, right? That's what a beer costs, buy your bike a beer.
    wilks3
    :USA
     
  3. iron_ty

    iron_ty Member

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    Not that I wouldnt buy my bike a beer, I'd buy it a few, I like it.. was just wondering if the higher octane fuel really did any good.. I've heard higher octane fuel is only necessary for higher compression engines.....883 compression is under 9:1 didnt know the ecm would change if I changed octane levels. Manual says 91 octane, so I guess thats what I'll keep burning.
     
  4. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Try running 89 octane, your EFI and Electronic Computer Management system detects if knocking occurs and will retard timing to compensate quickly...but if you are savvy, you'll hear a few pings before it goes away, under heavy load and throttle when riding two-up or accelerating a steep grade in high gear it is doing its's job and telling you to use 91 octane. If you do not hear pinging 89 octane is fine...run a few tankfulls to be sure. Only when I travel outside my normal area do I always run high test...don't want to pick up bad gas on the road.:s
     
  5. lionscar

    lionscar Member

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    Its all expensive in the Uk but I only ever use premium or what we call super-unleaded, octane over 91. Ive had to use normal fuel from supermarkets etc in emergencies before but if you know your bike well you will notice a difference, my Dynas a carb model so no fancy electronics to compensate for poor fuel it just runs rougher, hotter and slower and it would only save a few quid a month. No contest.
     
  6. Dswartz

    Dswartz Active Member

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    That's funny...lol
     
  7. dbmg

    dbmg Experienced Member

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    After already spending big $$$$$ to get the Harley and add more $$$$$ in accessories, why bother over $.20 per gallon....
     
  8. R_W_B

    R_W_B Senior Member

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    You can do a search there is another thread that covered this to exhaustion. But granted the high compression thing was what high octane was first created for back in the late 60's. But on your air cooled harley with emission mixture settings there are other factors involved that cause HEAT.

    The compression thing is really just an indirect reference to heat since compression causes heat, hence high compression diesel engines don't need spark plugs they just inject the fuel into a highly compressed air. The direct issue is that heat can cause pre-ignition and octane makes the gas ignite slower. In other words regular cheap gas is actually more combustible. The octane additive slows the combustion so as to prevent pre-ignition from heat.

    I burn 93 octane (if possible) in mine. I didn't always, but I started noticing a slight ping in the heads when I would go full throttle. I also like Shell brand gas since it has other additives that help keep the injectors clean.

    Just listen for pre-ignition knock, if you have it, then you need more octane in the mix. Pre-ignition knock ignored over a long period of time can burn a hole in the top of the piston.
     
  9. Hoople

    Hoople Account Removed

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    According to the list of 2010 Delphi tuning files, an XL883 does not have Ion knock retard circuitry. Your 2011 may be different. If your coil has only 3 wires going to it, you do not have protection from detonation so be careful. Depending on your helmet and or pipes, it can be hard to hear detonation.

    If I am tuning my engine, I wear my "beanie" helmet..
     
  10. R_W_B

    R_W_B Senior Member

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    Well there you have it, the most elite human DVD database has just illuminated your issue even further so you can take the prescibed precautions. That was all news to me since I didn't even know the 'any' ECM corrected from pre-ignition. It must do it a little after the fact cause I still have heard the ping on full throttle.

    Try putting your head down next to the gas tank when accelerating (be carefull to keep you eyes on the road) . I find I can hear much more stuff when I do this. Don't lean to the left of the tank or the primary whine will drown out some of it. But try to turn your ear to the tank, it will be a distinctive ping ping or in some cases more like a knock knock. If you are not sure just burn high Octane, there are no negative effects to that.

    Thanks Hoople wish I could organize everything I save from your posts.