Spewed Oil

Discussion in 'Engine, Fuel and Exhaust' started by Bartman420, May 25, 2015.

  1. Bartman420

    Bartman420 Member

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    What might be the culprit of causing the motor to spew oil through the air filter when the bike is running down the interstate? Air breather element is open, no cover. Did it one time, Cleaned everything up, got back on the bike and road another 35 miles home and never did it again. Occasionally hit 70-80mph on the trip after it spewed the one time.
     
  2. Jeff Klarich

    Jeff Klarich Well-Known Member Contributor

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    Sometimes if you run to much oil it will blow out the air cleaner. Many will run a 1/2 qt lower than called for just for that reason.
     
  3. Bartman420

    Bartman420 Member

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    Just ran a compression check.....185 front and back. Looked at the plugs......look fine. Jeff I think you're onto something.
     
  4. Jeff Klarich

    Jeff Klarich Well-Known Member Contributor

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    185 are respectable numbers. My scoot calls for 4 qts with the filter, when I change I refill with 3 1/2 qts with the filter and have never had any issues with oil blowing out the air cleaner.

    Others may chime in with their opinion as well. Good luck and let us know what you find.:s
     
  5. Jack Klarich

    Jack Klarich Expert Member

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    Most common cause is too much oil, try about 1/2 qt less in the oil tank next oil change
     
  6. Jack Klarich

    Jack Klarich Expert Member

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  7. dolt

    dolt Senior Member Contributor

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    Could very well be over fill but I don't subscribe to the "run 1/2 quart low" theory. If the manufacturer calls for 4 quarts, the motor should run fine, without belching oil, with 4 quarts. Running 1/2 quart low may solve the oil belching problem but is eliminating a symptom and not necessarily addressing the issue.

    The first couple of years the head breathers under the rocker supports were aluminum but were replaced with plastic units in '02 or maybe '03. Another bean counter bran fart decision from the MoCo; just not sure of the change year. The plastic units would warp from heat and lose their efficiency and, depending on mileage, the umbrella valves can harden and lose their seal as well as the breather mesh becoming clogged. In either case, sustained higher rpm running could "out run" the breathing capacity of the head breathers and result in oil puking out the air filter.

    It is an easy thing to replace your breathers with the new stamped units (PN26500002). The later breathers are more efficient and have cured the oil puking problem for others. Just a suggestion as I don't believe that running a 1/2 quart low on oil is a good idea for an air cooled vtwin.:coffee
     
  8. Bartman420

    Bartman420 Member

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    Dolt, the breathers were changed to the latest and greatest version this past winter. I was wondering about that but he produced the information on them being replaced.

    The backing plate for the air filter is an Arlen Ness, has the chrome breather bolts and vents into the throttle body. I think they call it a Big Sucker. Air filter came from Zipper. Could a different vent and backing plate be a viable option? Less likely to happen again? Vent it to atmosphere?
     
  9. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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