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  1. #1
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    250XS running rich

    Year model 2007 Serial # 1E003251 500+hrs

    Long story short engine quit like the kill switch was pulled while getting on plane...dead in the water. Got it home and found I had blown the 20amp fuse in the #4 position (Electric fuel pump, etc.) Fuse blew due to heat from a loose fuse holder connection and it was 11 years old. I tighten up the fuse holder so the fuse plugged in tight. Engine fired right up on the hose all looked and sounded good no alarms,so I thought I was good to go. Wrong...next trip out I could not get up on plane. Home again to trouble shoot the basics. Motor fires right up every time no warning horn but seem to idle a little rough.
    After idling on the hose for 5 min or so here are some findings. I removed all of the spark plugs and they all were wet with fuel and starting to turn black similar to when they foul. In the past whenever I pull the plugs to inspect they are dry a very light tan.
    The other thing a noticed was fuel coming from the air pressure Schrader valve on the fuel rail when I took a pressure reading. Is that normal to have fuel present at that valve?
    I'm pretty sure I have eliminated the ignition system, seems to be an excessive fueling issue, just my guess.

    Any help would appreciated, Don and the folks here always seem to be a great help.

    Notes
    -New Plugs installed, reeds, pulse fuel pump, water pump, oil pump, all completed this year and Dons cocktail all ways. Motor has not had any previous issues.
    All Coils provide good to spark tester
    Compression 120-125 on all cylinders
    Plugs gapped to .044
    New plug wires
    Quality fuel
    Fuel pressure at rail valve 109psi @ idle
    Air pressure At rail valve 95psi @ idle
    Last edited by cannon20xrd; 07-10-2018 at 03:16 PM.

  2. Member
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    #2
    Possible tracker valve diaphragm. Need air and fuel pressures tested.



  3. Member
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    #3
    Hey Savage,
    Will a bad tracker valve diaphragm allow fuel into the air pressure Schrader valve ?

  4. Member
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    #4
    Tracker valve diaphragm and housing look good no tears or hole in diaphragm. No trash in the housing but there was a small about water in the housing.
    Condensation ? Still try to narrow the issue down...suggestions ?
    Last edited by cannon20xrd; 07-09-2018 at 06:07 PM.

  5. Member
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    #5
    I will try to get the fuel and air pressure numbers under acceleration ASAP.

  6. Member
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    #6
    Any other suggestions ? Before I bring it to Don.

  7. Member
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    LONGVIEW TEXAS
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    #7
    no fuel at air scrader, lil condensation is normal, several other things can put fuel there [regulators]
    .................................................. ...the scariest thing in life is the unknown ...................................

  8. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #8
    Quote Originally Posted by cannon20xrd View Post
    I will try to get the fuel and air pressure numbers under acceleration ASAP.
    Record results for:

    -At idle
    -Under Acceleration
    -5 Seconds after shutdown (then restart)
    -10 Seconds after shutdown (then restart)
    -15 Seconds after shutdown.


    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

  9. Member
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    #9
    Issue resolved, it turn out to be a bad plug wire. On the spark tester the plug wires hung straight and everything tested good.Once the plug wires were connected to the plugs and the wire was given a 90 degree " U" bend, spark was dead on one plug. While trouble shooting the issue I removed the plug wires at least half dozen times changing out plugs, plug inspection,coil inspection and so on. I suspect all this manipulating of the plug wires caused the failure. The plug wires were originals so they were due, no complaints here. I was hauling up to see Mr Weed if I didn't win last weekend !
    Thanks to all.

  10. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #10
    Love those simple solutions.


    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