VFR 800Fi - throttle stuck by itself - literally!

Discussion in 'Mechanics Garage' started by cryptorchid, Apr 18, 2022.

  1. cryptorchid

    cryptorchid New Member

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    I parked up my VFR for the winter period after a 50 mile run - no issues, running like clockwork as always. After a couple of months, while it has been covered up and untouched , I went to start it up and get it ready for it's MOT. Started up straight away as usual, with a minimum of choke, BUT the throttle is jammed shut. I have checked the throttle assembly at the handlebar, raised the tank and disconnected the throttle cables, and checked the movement of the choke. Everything is free and easy, but the throttle cam on the throttle body is stuck solid and will not rotate. I have tried running up to full temp to see if it would 'unstick', but to no avail.

    It makes no sense at all, has anyone had a similar problem, or got any bright ideas? Thanks in advance!
     
  2. Terry Smith

    Terry Smith Member

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    Certainly sounds like you've checked the right things externally. Next step would be to remove the airbox and expose the throttle bodies; maybe some critters have moved into the airbox over winter and filled the intakes with stuff?
     
  3. squirrelman

    squirrelman Member

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    ^^ he's right on target, our terry !

    if some mouses nested in your airbox over the winter and peeed there too, there may be damage as mouse pee is very corrosive.

    aug 1 2020 011.JPG
     
  4. cryptorchid

    cryptorchid New Member

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    It's only taken me a month to take the air box apart, but it would seem that you fine gentlemen were right. The mouse pee has corroded the two front butterfly valves shut. Careful cleaning and some WD40 should do it (hopefully).

    IMG_20220517_172601-edit.jpg IMG_20220517_172432-edit.jpg IMG_20220517_172656-edit.jpg
     
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  5. Grum

    Grum New Member

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    YUK! That looks disgusting!
    Be very careful when cleaning the Throttle Butterflies that you do Not damage the black Molybdenum seal compound for the butterflies, this will result in air bypass and high idle issues, and messes with the Starter Valve synch.
     
  6. cryptorchid

    cryptorchid New Member

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    Thanks for the heads-up, I'll be careful.
     
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