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  1. #1
    Cadet
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    Feb 2010
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    Default Johnson 88, 6HP Carb pissing fuel out

    Hello to all, friend has asked me to help him with his outboard,
    The engine is poorly, and i have no experience with outboard Carbs, only motorbike carbs,



    marked in the picture where the fuel is leaking out like mad, took the carb off this morning to check floats and float valve all good, and #29 (in picture) i cant remember seeing, but that was just from a quick think, what does this part do?

    the engine runs but will not fully rev out, sputters and tries but is not revving much higher than tick over even with throttle fully open,

    Im thinking a blocked jet maybe?? thats why i have posted this as all information will be greatly appreciated, Thanks for looking, Ian

  2. #2
    Captain
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    May 2004
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    Default Re: Johnson 88, 6HP Carb pissing fuel out

    The areas you have ringed and indicated fuel to be leaking from is the float chamber vent.

    For it to be leaking from there I dont think that the float and needle valve can be controlling the fuel entering. I'd look again more carefully at those.

    #29 is a gasket
    Vic

  3. #3
    Cadet
    Join Date
    Feb 2010
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    Default Re: Johnson 88, 6HP Carb pissing fuel out

    Many Thanks Vic.S for getting back so quick,



    so the curved pit pictured above is a vent for the float chamber, the reason for fuel comming out is beacuse the float chamber is recieving far to much fuel and escaping through the vent, sorry for sounding dumb just working out how these carbs work lol, also i have highlighted two nipples where fuel/return pipes connect, just make sure that we have the fuel lines connect properly,
    Thanks Again Ian

  4. #4
    Cadet
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    Feb 2010
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    Default Re: Johnson 88, 6HP Carb pissing fuel out

    Has anybody got any ideas??

  5. #5
    Captain
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    May 2004
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    Default Re: Johnson 88, 6HP Carb pissing fuel out

    #14 is the connection to the primer pump (it has pump type primer rather than a flap type choke) the other nipple you have marked is the feed to the carb from the fuel pump.

    if you are sticking the fuel in the wrong place it would explain the flooding!

    Its all slightly different to mine. That has the flap type choke so no connections for a primer pump and the float chamber vents back to the air silencer box, I think!
    Vic

  6. #6
    Supreme Mariner
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    Sep 2003
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    Default Re: Johnson 88, 6HP Carb pissing fuel out

    The primer system is a hand pump; so unless you keep pumping it, it should not flood the carburetor.

    The float (25) should lift as the fuel rises in the float bowl (17), pushing the needle (21) closed to stop fuel from entering the carburetor until the engine has pulled enough fuel through to lower the float again. Fix that first to keep from flooding the carburetor.

    With the carburetor upside down, the float arm should close the needle valve so that you cannot add fuel (or air) through the primary fuel nipple.

    The float should be positioned such that when the carburetor is upside down, the float is parallel to the base of the carburetor body.

  7. #7
    Cadet
    Join Date
    Feb 2010
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    6

    Default Re: Johnson 88, 6HP Carb pissing fuel out

    Cheers guys!!!! will do all checks tomorrow

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