Evinrude 7.5 idle

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    james hobson


    Replies: 13
    Topics: 3
    #227035

    My 7.5 does not want to idle I cleaned carb and rebuilt new points coils condenser still won’t idle 1956 evinrude ; any tips

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    crosbyman

    Canada Member - 2 Years
    Replies: 1827
    Topics: 216
    #227036

    idling requires fuel delivery from the low speed side of the carb did you try adjusting the LS needle

    are you using a pressure tank or a converted to fuel pump set up ??

    cleaning the complete low speed fuel route involves pullling the top dime size cap and cleaning the low speed drip chamber did you do that ?

    is this a new /recent issue with the motor ? how is compression ?

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    fleetwin

    US Member - 2 Years
    Replies: 3598
    Topics: 35
    #227038

    Well, the possibilities are endless….
    So, always start with the basics like compression. Have you checked spark, replaced the plugs? Are you sure the engine is running on both cylinders? Does the engine run properly at high speeds? Does it sneeze and cough at idle, or just run crappy and stall? Anyway of posting a video of the engine misbehaving at low speeds? When was the last time it ran properly?

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    reivertom

    US Member - 2 Years
    Replies: 695
    Topics: 37
    #227049

    Check the compression. If it is low, it will run faster, but won’t idle worth squat.

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    james hobson


    Replies: 13
    Topics: 3
    #227093

    Use I use pressure tank Clean carb clean LS took plug out still idles crappy runs good at high speed .

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    james hobson


    Replies: 13
    Topics: 3
    #227094

    Runs crappy and stalls , replaced plugs points condenser rebuilt carb set timing.

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    james hobson


    Replies: 13
    Topics: 3
    #227095

    Definitely running on both cylinders; does not spit and cough just lidles crappy and dies

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    crosbyman

    Canada Member - 2 Years
    Replies: 1827
    Topics: 216
    #227098

    well what are the compression numbers ??? if electricals are OK we can assume it is not sucking fuel properly to feed the cylinders

    check all negative pressure points…

    a- starting at the fuel pick-up (change tank and hose if neeed be )

    b – divide to conquer…. feed the carb manually with a small fuel supply and hose to the carb inlet thus bypassing the, air pressure pulse , hoses and pressure tank as a problem source

    if idling is ok work backwards . low pressure pulse feeding the tank (bad check valves behind the inlet manifold)

    c- if still idling bad with a small fuel supply on the carb inlet …….. problem is on the engine side

    d- possible loss of crankcase negative pressure causing a weak pull on the carb idle circuit fuel supply ( crankshaft bearings allowing external to be sucked in the crank case instead of fuel from the carb)

    e– carb gasket not sealing , LS needle packing inadequate sealing,

    f- check the throttle plate at the rear of the cab .. it should be pretty well closed at idle to have the fuel sucked out of the idle chamber

    g- btw did you clean out the VERY small jet in the side fuel channel feeding the upper half of the carb ? (look closely inside the feeder
    channel) clean it out with a VERY VERY small wire and flush with carb cleaner and air pressure blast

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    • This reply was modified 2 weeks, 2 days ago by Avatarcrosbyman.
    • This reply was modified 2 weeks, 1 day ago by Avatarcrosbyman.
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    crosbyman

    Canada Member - 2 Years
    Replies: 1827
    Topics: 216
    #227101

    see info on bleeder valve and poor idling

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    dave-bernard

    US Member - 2 Years
    Replies: 1281
    Topics: 17
    #227105

    or could it be flooding at idle ?

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    crosbyman

    Canada Member - 2 Years
    Replies: 1827
    Topics: 216
    #227110

    could be….” clean the carb” don’t mean much I guess…. one presumes it was adjusted…right ?

    time for a blow test if not a downstream issue πŸ™‚

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    lloyd

    US Member - 2 Years
    Replies: 253
    Topics: 1
    #227111

    The three paramount factors for engine performance are: Compression, Ignition, and then Carburetion in that order. Why waste time and money building a proper ignition for a motor with low compression??? Why waste time and money rebuilding a carburetor for a motor that has no ignition????

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    crosbyman

    Canada Member - 2 Years
    Replies: 1827
    Topics: 216
    #227114

    without answers to most above ??? it is all a guessing game. carb and ignition apparently done ?? compression #s still unknown hopefully good enough . we don’t even know if this is a new problem , a new to me engine…etc…

    patience brings joy

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    outbdnut2

    US Member - 2 Years
    Replies: 1398
    Topics: 74
    #227126

    Does the idle change at all when you adjust the low speed idle needle? If it does not change, that is a big clue.

    Can you find a choke setting that makes it idle better – another big clue.
    Dave

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    james hobson


    Replies: 13
    Topics: 3
    #227141

    Ok I get it i will check compression is a simple screw in the cylinder pull the rope good enough or should I do a leak test, should motor be hot warm cold, can you run engine on one cylinder and check other one for compression check any tips would be helpful, thanks

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