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  1. #1
    Petty Officer 2nd Class
    Join Date
    Nov 2008
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    133

    Default Why change to adjustable low speed jet?

    While looking into parts compatibility for my Johnson 70, I noticed that OMC switched over to an adjustable low speed jet sometime during 1989. Does anyone have insight into why the changeover? Were the fixed-jet motors not performing satisfactorily?

    Tim

  2. #2
    Honorary Moderator Emeritus tashasdaddy's Avatar
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    Nov 2005
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    Jacksonville, Florida
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    51,017

    Default Re: Why change to adjustable low speed jet?

    if i am not mistaken they have the fixed jet, that is an idle air mixture adjustment, that most newer J/E's have.
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  3. #3
    Petty Officer 2nd Class
    Join Date
    Nov 2008
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    133

    Default Re: Why change to adjustable low speed jet?

    Quote Originally Posted by tashasdaddy View Post
    if i am not mistaken they have the fixed jet, that is an idle air mixture adjustment, that most newer J/E's have.

    I think you're right - I was sloppy in my terminology. Same question applies, though - why did it become adjustable midway through the 1989 model year, after previously being fixed? I would think the adjustable version is more expensive; seems like OMC would not have made such a change without a good reason.

    Tim

  4. #4
    Seaman Apprentice
    Join Date
    Jan 2007
    Location
    lockhart,texas
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    46

    Default Re: Why change to adjustable low speed jet?

    well,...in my opinion,.........this allows u to adj to diff situations,and as the eng ages,wears,....u r able to compensate and fine tune,for better idle.

  5. #5
    Supreme Mariner
    Join Date
    Jul 2006
    Location
    Florida Gulf Coast
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    19,308

    Default Re: Why change to adjustable low speed jet?

    My humble observation says that people just gotta have something to monkey around with. They even tried to "adjust" the screw plugs over the fixed idle jets. Give 'em what they want.

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