Free Revving A harley

Discussion in 'Touring Models' started by quiticokid, Nov 17, 2012.

  1. quiticokid

    quiticokid Member

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    Why is free revving up a harley like they do at the Buffalo Chip concerts bad for the bike? I told a friend that I heard this is not a good idea because you might blow the bike up but he claims that if you keep the rpms at a reasonable range that this hurts nothing. Any experts on the subject out there?
     
  2. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

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    It isn't good for bearings,cams,connecting rods to rev any internal combustion engine while not under load.
    They are meant to work under load,you get a free rev. vibration when revving while not under load and this does the damage,excessive free revving has also been known to crack pistons and cylinder heads.
    At the very least it will have a blow by effect where the unburnt gas will get past the piston rings and find it's way into the motor oil.
     
  3. glazier

    glazier Junior Member

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    Other than all that, what's the downside??? :lero
     
  4. RockinRich

    RockinRich Member

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    Why would you want a Harley if you couldn't rev the motor at every light or any time you aren't moving?
     
  5. Midnight Reign

    Midnight Reign Active Member

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    The reasons Steve cited for not free reving a harley are all valid, there is however another reason of great importance for not doing this. Harley crankshafts are more complicated than say a small block chevy that most are familiar with. The major difference is that a Harley crank is made in multiple pieces, pre-twin cam were at least 5 pieces, and both pistons share a common crank pin. All of these pices must be aligned correctly for the motor to run smooth enough that it doesnt shake itself to bits. Free-reving and especially the rapid deceleration from said free-reving can cause 1 or more of the many parts in the rotating assembly to come out of alignment. You have to keep in mind that a Harley is not much more than steam engine technology, albeit at this point probably the pinacle of its developement.
     
  6. glazier

    glazier Junior Member

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    I don't know about you, but I didn't just spend almost $30,000 on my brand new bike so I could just rev the motor at every light. I bought it to ride, and if revving the motor is not good for it and I won't get the maximum number of years or mileage out of it, then why do it??? I'm too old to try to impress the little girls sitting next to me at the red light (but their mother might be a different story) :s
    So, I don't see the point of just revving the motor for no reason, even on my old Heritage. What is the point??? Now if I'm at a light for a long time or stuck in traffic, I'll give it some gas to keep the oil flowing. But these are jmho. To each his own.

    Rev away if you like
    It's your bike
    Or get a trike
    and be like Mike :)
     
  7. marknett

    marknett Active Member

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    Ok .. no revving , but what about the hog snort ... does that count :small3d015:
     
  8. RibEye

    RibEye Junior Member Contributor

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    If you are ever present at a dyno-tune, you will develop PTSD. Talk about long term reving...My poor baby...

    Enjoy,
    Rich P
     
  9. titan307

    titan307 Member

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    are you talking about giving your bike a little tweek say at a light or as just a little hey looka at me? if so thats not going to hurt , nothing wrong with a quickie every now and then. But if your talking about free revving like the crotch rocket crowds, then NO it is not good. Crotch rockets are built for performance and therefore the parts are made for abuse.
     
  10. marknett

    marknett Active Member

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    Thats what I;m talking about .. got to let the pig snort every once in a while
    :s