Humming When Ignition On

Discussion in 'Technical Help' started by Bret Morey, Apr 20, 2019.

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  1. Bret Morey

    Bret Morey Well-Known Member

    Apr 20, 2019
    97
    83
    Alexandria, PA - USA
    I just recently picked up a Scrambler 1200xc. This is my first fuel injected ride, so I am clueless. Hoping someone here can either put my concerns to rest, or tell me I need to get the bike into the dealership. The question I have is about the sounds the bike makes when you flip the ignition on. I push up on the "on switch" and my electronics wake up. Then I push it down into the run position, and I can hear what I assume is the sound of the fuel pump running for a few seconds and then it shuts off. Once the fuel pump stops running you can hear a hissy/humming/ squealy sound that is constant. It almost sounds like like high pressure air leaking through a tiny leak; and at times almost sounds like the squealy sound of dodgy electonics.

    Is this normal? If so, can anyone tell me what I am hearing.

    Thanks.

    -Bret
     
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  2. Red Thunder

    Red Thunder Crème de la Crème

    Dec 2, 2014
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    #2 Red Thunder, Apr 20, 2019
    Last edited: Apr 20, 2019
    I suspect that would be the throttle position sensor (TPS)
    As said, the fuel pump primes then there is the whine of a small electric motor (although not constant) I believe this is the TPS as it does a self check

    Does this every time I switch my Speed Triple on

    So all normal and nothing to worry about

    I could be talking bollocks but I do get the same squealing high pitched noise at each start up on both Speed Triples I have owned so I hope it is normal

    Edit: I think the valve is the Idle Air Control valve, opening the throttle body just enough to maintain tickover
     
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  3. brown mouse

    brown mouse Elite Member

    Sep 15, 2018
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    East Midlands, UK
    I get that constant hissy/humming/squealy noise on my Bonnevile Speedmaster (essentialy the same 1200 engine as yours I believe). Sounds to me very like the squeal you get from high frequency electrical transformers. I've assumed the noise was normal, but it does sound rather unnerving. Probably should actually ask next time I'm at the dealers.
     
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  4. Red Thunder

    Red Thunder Crème de la Crème

    Dec 2, 2014
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    Idle Air Control valve

    This what I meant to say it was in my earlier post
    This is a little motor that controls the air to the throttle bodies when the throttle is completely closed, essentially controlling the opening needed to maintain a constant tickover
     
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  5. brown mouse

    brown mouse Elite Member

    Sep 15, 2018
    2,288
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    East Midlands, UK
    The noise I hear is without the engine running, just turning the ignition on. I'm not completely sure, but Bret's original message is talking about using the engine kill switch (I never use that) but not starting the engine (?).

    If we are talking about the same conditions, then I would say it seems a little odd that there should be noisy activity around the injector area before the engine is started. But then, mines always done that, and I've done 6000+ miles without engine running problems :)
     
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  6. andypandy

    andypandy Crème de la Crème

    Jan 10, 2016
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    You say it hums, can you recognise the tune ? That would give us a bit more to go on. ;);)





    Sorry. :D
     
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  7. Bret Morey

    Bret Morey Well-Known Member

    Apr 20, 2019
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    Alexandria, PA - USA
    To all but andypandy, Thanks for the affirmation that this is normal. Now that you all mentioned possible sources I got thinking more and realized it does actually sound like a high frequency, high precision, high torque servo working to maintain position.

    To anypandy, It's either Mary Had a Little Lamb, or Breadfan; but I'm not sure which.
     
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  8. BigCLM

    BigCLM Senior Member

    Nov 30, 2017
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    San Rafael, CA
    Probably just the fuel pump running . Normal.

    My Street Twin has a similar sound. Fuel pump running. Been riding it for over a year now and 5,000 miles with no issues. But if you are still concerned take it to a dealer for a check up. Or turn the key on a new identical bike at the shop and see if it has the same sound.
     
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  9. andypandy

    andypandy Crème de la Crème

    Jan 10, 2016
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    My Street Triple goes on making weird noises for ages after I've turned the ignition off and I'm not talking about cooling ticks. It sounds like R2D2.
     
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  10. Bret Morey

    Bret Morey Well-Known Member

    Apr 20, 2019
    97
    83
    Alexandria, PA - USA
    Just to be clear. The noise I hear is before I ever start the bike. The new 1200 is keyless, so you push up on a switch to turn on the dash and lights, the push down on the switch to put the engine in "go mode", after that you can push down further on the switch to start the motor. The sound I here is when I do the first click down on the switch but before I push down further to actually start it. At first you hear the fuel pump run for 2-3 seconds, then once the fuel pump kicks off I hear the high pitched oscillating whining sound.
     
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  11. Ducatitotriumph

    Ducatitotriumph Crème de la Crème

    Apr 25, 2019
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    Hi there, I've also noticed this noise on my speed triple rs.
    I know it sounds bonkers but (on mine at least) its coming from the TFT screen. Yep, really!
     
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  12. Yorkshireman

    Yorkshireman Crème de la Crème

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    Oh joy, summat else for Triumph to sort outo_O
     
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  13. joe mc donald

    Subscriber

    Dec 26, 2014
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    Bret Morey.
    Welcome to the Family if I have not said it before. But my Bonneville does exactly the same as soon as you turn the key on away it goes singing and hissing. Not really bothered me as I did assume it was just the machine talking to itself and getting ready.
    Ride Safe & Enjoy
    Joe.
     
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  14. SuperHans

    SuperHans Senior Member

    Mar 11, 2020
    297
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    Sweden
    Just picked up a 2016 Speed Triple and found this high pitch sound when I turn on the ignition.
    My old Speedy doesn't have this sound.

    Guess its nothing to worry about after reading this thread.
    Just wanted to do a quick post and say thanks, saved me a trip to the mechanic, cuz it does sound like something it broken.

    It does seems like this is "normal" for some cars and bikes after reading about it.
    Did a search for "high pitch sound throttle body" and you get a lot of hits.
     
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  15. Ian Li

    Ian Li New Member

    Jan 31, 2022
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    US
    #15 Ian Li, Jan 31, 2022
    Last edited: Jan 31, 2022
    Hello, is there any update about the root cause of this phenomena? I just noticed this on my 2018 Bonneville T100 (under 3k miles) in my seventh month of ownership, and Google leads me to this post.

    The noise starts when turns on the bike (no matter by key or by switching the engine start/stop switch from STOP to RUN position), even before the self check completes. I've made a video:


    I am not sure whether it's still there after the engine started.
     
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  16. joe mc donald

    Subscriber

    Dec 26, 2014
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    Yes my 18 bonnie does the same even louder sometimes and yes even when i pull in for petrol and take the key out it still sings for a moment or so. Just the norm. All the gadgetry talking to itself and sending signals to the bikes brain.
    Joe.
     
  17. brown mouse

    brown mouse Elite Member

    Sep 15, 2018
    2,288
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    East Midlands, UK
    Noise is normal, mine sounds same. For these ride-by-wire throttles I reckon it's the servo that operates the butterfly valves in the throttle bodies. Well, that's my theory anyway. If I remember correct, twisting the throttle with engine off makes the whine change, which is probably why I came to the butterfly valve servo theory.
     
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  18. Andrew G

    Andrew G New Member

    Dec 25, 2023
    0
    1
    TN
    I don't think this is normal as my bike just recently started doing this. I went to ride and discovered that my battery didn't have enough juice to start, so I jumped it. I noticed that my fuel gage was way off and reading 3 miles worth of fuel when it was at 50 miles before the jump. I rode for 30 mins and it did not reset. I also noticed a similar sound as in the video had statmrted when the bike was in the run position and does not stop. I think it's coming from the throttle positioner as leakby from a faulty relay or something. I'm think of seapping out the whole assembly
     
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