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Evinrude 4 hp -74 carb adjustment

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  • Evinrude 4 hp -74 carb adjustment

    According to my manual there should be a needle valve for "high speed adjustment" at the lower part of the carb.On my carb there is only needle valve for "low speed adj." At the hole for high speed there is a plug which canĀ“t be adjusted. Is this some kind of modification or do I have to get a needle valve. IĀ“m still rebuilding the motor and havenĀ“t tried starting it yet.

  • #2
    Re: Evinrude 4 hp -74 carb adjustment

    Hi Speed Your model has a non-adjustable hi-speed orafice. Most of the time once is adjustment was made, there was no need to change it. So they (OMC)quit using the needle valve. One of the only times you might need this feature is for running at extreme elevation differences. You know, sea level one day the rockies the next. OMC did offer a kit to install a needle valve if necessary. I don't know if it is still available. They also offered different sized orafices. Unless you plan to have this extreme situation you shouldn't need to worry about this. Just clean and service your carb, it sould be good to go.


    • #3
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      Re: Evinrude 4 hp -74 carb adjustment

      Thank you alcan, for your reply!IĀ“ll have it ready for a test run in a couple of days