Thread: 300 xs

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  1. #1
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    300 xs

    2011 300xs serial # 1E051297.
    When I run somewhere an an shut it off for a bit an I go to crank it back it acts like it don't wanna start like it's flooded an then after couple attempts it starts an smokes for a couple of seconds an then fine. And sometimes it doesn't do it.

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    #2
    it is flooded ,most likely fuel in air side of system , several possible causes . tracker is known for this symptom
    .................................................. ...the scariest thing in life is the unknown ...................................

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    #3
    I checked tracker and it's fine I changed it when I had injectors and rails cleaned

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    #4
    procede testing for fuel in air side of system, inspect pulse pump diaphragm also
    .................................................. ...the scariest thing in life is the unknown ...................................

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    #5
    Clean your injectors.

  6. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #6
    Quote Originally Posted by Shuck Grass View Post
    Clean your injectors.
    Please read above posts.

    Dro10: You need to have the Air and Fuel Pressures checked, and results recorded for: Idle, Under Acceleration, and 5/10/15 seconds after engine shutdown (restart for each time period).

    The more precise the results, the better they can be accurately interpreted.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
    Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
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    #7
    Bleed down test will show if a issue with injectors bleeding down
    Ron Fears
    Stroker/300XS
    1E003823

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    #8
    AKA causing a flooding situation at startup
    Ron Fears
    Stroker/300XS
    1E003823

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    #9
    Update checked fuel/air psi they where 80 psi. Checked and found Fuel regulator diaphragm had small crack changed out an now I got 112 fuel psi an 90 air. An running great. Thanks for the tips

  10. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #10
    Might want to swap gauges and make sure the numbers still match that. If accurate, they're out of spec.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
    Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
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    #11
    What do the pressures need to be? Thanks I will check again

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    #12
    109 94 is factory spec with perfect gauges. If fuel pressure is higher I could lead to a lean or fat condition
    Ron Fears
    Stroker/300XS
    1E003823

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    #13
    Rechecked an fuel was 106 psi an air was 94 psi. What my guages showed an switched them out
    Last edited by dro10; 04-23-2023 at 07:43 PM.

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    #14
    Should be a 15psi split
    Ron Fears
    Stroker/300XS
    1E003823

  15. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #15
    If results are identical with gauges swapped... you have a fuel pressure problem (likely in the Fuel Pressure Regulator).

    I would recommend that you re-check the pressures one more time at 1000-1100 RPM's. That's the recommended calibration point.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
    Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
    Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor