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  1. #1
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    115 pro xs water pressure problem

    <2B556826> I replaced my impeller earlier this spring and ran the boat twice with no issues ...took it out today and noticed once i was on pad and started to trim up my water pressure plummeted quickly from 20+ to around 7 . i usually see just under 20 fully trimmed out. Should I yank my lower unit and impeller again? Any thoughts?
    Last edited by EuropeanAM; 05-05-2021 at 10:54 AM.

  2. Member
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    #2
    Impeller was fine ....need help locating the poppet valve if anyone has a picture of where its located on a 2018 that would sure help.

  3. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #3
    If you would, please be sure to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

    Better check the gasket BELOW the impeller plate... it's often the source of sudden loss of water pressure.


    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

  4. Member
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    #4
    Sorry 2b556826...when i did my impeller kit the bottom gasket was a hard black plate and the top gasket was a soft rubber one was this wrong?

  5. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #5
    Top gasket would normally be a fiber gasket with a thin silicone sealing ring on the top-side. Correct orientation is critical, and lower gasket (metal) should be applied with Perfect Seal (or Permatex Aviation Sealant). The Face Seal (atop the pump) must be seated with the correct tool (or at precisely .350" height above housing).

    And impeller should be lubricated with ONLY Dishsoap (preferably Dawn). No grease or oil. Impeller blades must be folded over for a CLOCKWISE shaft rotation (and variations in the above info would necessitate pulling it back down).


    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

  6. Member
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    #6
    Resealed lower gasket with perfect seal ...everything is operation normal... thanks