Knocking in the cylinders...

Discussion in 'Sportster Models' started by HDSportster1200, Dec 27, 2009.

  1. HDSportster1200

    HDSportster1200 New Member

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    I hear a knocking sound when the engine is running. What is causing this?

    John
     
  2. kemo

    kemo R.I.P

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    Being as it is a 1200 conversion could be a loose piston. Did the knock start after the conversion?
    kemo
     
  3. maine-e-axe

    maine-e-axe Junior Member

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    Could be a peice of carbon came loose as well, try spraying water with a mist into the carb while keeping it running for 3 to 4 minutes, it should break it up and blow it out the exhuast. Maybe that easy, maybe not.
     
  4. Hoople

    Hoople Account Removed

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    I would temporary throw a mechanical oil pressure gauge on it just to see if its a bad pressure fed bearing. Is the sound in syc with crank RPM.
     
  5. Jack Klarich

    Jack Klarich Expert Member

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    Ive seen a lot of broken piston skirts on these sounds like a slapping primary chain