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  1. #1

    Default 1979 Mercury 40hp 402 2 cycle

    I'm having a problem with my carburetor leaking fuel out of the float bowl when you pump the ball.

  2. #2
    Join Date
    Nov 2005
    Chesapeake, Va, US

    Default Re: 1979 Mercury 40hp 402 2 cycle

    You need to rebuild the carb. Clean thoroughly and reassemble using new gaskets, needle and seat. Be sure to check the float while you have it apart for fuel intrusion and adjusted properly when reassembling.
    Bill H PTC USN Ret
    A manual is a cheap investment.

  3. #3
    Join Date
    Sep 2003
    New Tripoli, PA, USA!

    Default Re: 1979 Mercury 40hp 402 2 cycle

    You can hand pump that carb to 15 pounds pressure, where the motor only develops 4. Most carbs will do that if you pump too hard. Long as it doesn't leak when the motor is running it's okay.


    PS: I lower the float level 1/8 inch on mine when it does that.

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