Oil coming out of air filter

Discussion in 'Oil' started by Varedneck, Sep 27, 2010.

  1. Varedneck

    Varedneck Member

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    I have a 96 Fatboy EVO with oil coming out of my air filter and blowing back on the oil tank, muffler and everywhere else when I run around 70 miles per hour. The air filter is a K&N however it is mostly dry all the time. What could be causing this.
     
  2. Jack Klarich

    Jack Klarich Expert Member

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    Over full oil tank, umbrella seals in rocker boxes, remember when changing oil, there is about 1 qt of oil left in the crank case, try a bit less oil and see hoe it does, also check the hoses that run yo the backing plate of the AC for weak and or kinks:D
     
  3. Varedneck

    Varedneck Member

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    The oil tank level is good, so how hard is it to repair unbrella seals? Thanks Jack
     
  4. Jack Klarich

    Jack Klarich Expert Member

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    Do you have a manual and a Torque wrench. If yes do it its a good thing to be able to wrench on your own bike and get to know it a bit better JMO:s
     
  5. sprinklerfitter669

    sprinklerfitter669 Junior Member

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    Are you checking the oil when it is cold, or warmed up..:s
     
  6. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    If it is only happening at 70+ mph i would start by doing a compression test if there is some bore wear or damaged piston rings then some of the gasses caused by ignition will bypass the rings and pressurise the crankcase as the piston goes down the pressure is increased and will blow the oil from the crankcase out through the breather
    if that is what is happening there would be no oil at lower revs and a lot at higher revs
    If however its a wee bit of oil all the time i would suspect the umbrella valves

    Brian