'57 Merc Mark 25 Carb Needed Valve Settings

Home Forum Ask A Member '57 Merc Mark 25 Carb Needed Valve Settings

This topic contains 4 replies, has 3 voices, and was last updated by Avatar wabittle 1 month ago.

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    wabittle

    Replies: 2
    Topics: 1
    #178923

    I am looking for someone who might know the initial carburetor needle valve settings for a 1957 Mercury Mark 25.

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    JayzonAych
    US Member - 1 Year
    Replies: 15
    Topics: 0
    #178924

    1-1/4 turns out from lightly seated on both low and high speed mixture screws usually is a good starting point for me on my Mercurys

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    dave-bernard
    US Member - 2 Years
    Replies: 876
    Topics: 10
    #178941

    I use 1 1/2 turns out. just me.

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    wabittle

    Replies: 2
    Topics: 1
    #178965

    Thanks guys for the info. I’ll try that setting.

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    wabittle

    Replies: 2
    Topics: 1
    #178984

    Aaah! I found an old Mercury shop manual and it states that the idle speed should be 1 turn out and the high speed is 1 1/2 turns out from seat position. Nothing like a shop manual … to bad no one fixes anything anymore and they don’t print them for much of anything! I can’t even get one for my 2015 Honda CRV.

    Again, thanks for all that posted replies. Your info would have most likely worked perfectly well too!

    Regards,

    Wade

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