Results 1 to 6 of 6
  1. #1
    Member 91@Storm's Avatar
    Join Date
    Feb 2015
    Location
    alva, florida
    Posts
    93

    Water pressure after rebuild (low)

    1998 225 EFI
    serial number 0G723446

    recently had my powerhead rebuilt and am in the process of finishing the break in. I’ve noticed that my water pressure is not as high as it was prior to the rebuild. At an idle the Guage shows 3 lbs and at WOT only shows 9 lbs. This is with the jackplate all the way down. During the rebuild a new water pump was installed. I have not gotten an overheat alarm and the motor has a strong stream out the back.

    I replaced the tubing going to the guage thinking i may have pinched it while rewiring my dash during the rebuild. No luck. So, then I replaced the gauge thinking I may have damaged the original during the rewire project. No luck. Prior to the this I would show 16-18 lbs at WOT.

    Before I take the boat back to the rebuilder is there anything I should be looking for?
    1991 Storm 20'6 ( Double Cheesy )
    1998 Merc 225 EFI
    Bob's Jackplate
    SIMRAD GO7
    Dual Power Pole Sportsman 2's






  2. Member
    Join Date
    Nov 2008
    Location
    Raleigh NC / Falls Lake
    Posts
    11,210
    #2
    In the past . Don has said go to the main source first .....water pump and check every thing .

  3. Member
    Join Date
    Jul 2004
    Location
    Penn PA
    Posts
    15,104
    #3
    Take it back.



  4. Member
    Join Date
    May 2011
    Location
    Spangle, WA
    Posts
    6,180
    #4
    Quote Originally Posted by Savage View Post
    Take it back.
    What I would do as well since new water pump was installed during rebuild.
    _______

    Phil
    '09 Hewescraft ProV
    '09 150 Optimax


  5. Member
    Join Date
    Jan 2014
    Location
    Madison Alabama
    Posts
    127
    #5
    I recently had a water pressure issue (torn gasket) so I swapped the pump and it got worse. The problem with the new pump was the new housing had a flaw where the lip on the bottom of it was too tall (had to measure it with calipers to tell the difference) so it wouldn't compress on the gasket. The symptoms were similar to yours, the idle pressure was ok (but not quite as high as normal) but the WOT pressure was low.

  6. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    94,945
    #6
    Do you have low water inlets in the nose of the gearcase? If so, those passages may have something floating around in them (such as wood).


    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