Results 1 to 4 of 4
  1. #1
    Member
    Join Date
    Mar 2020
    Location
    Bellevue, Ohio
    Posts
    152

    250 Pro XS Temps and Pressure

    Serial number. 2B526796

    So last weekend I bumped a sandbar and picked up some sand in the motor. Cleaned the thermostats out and ran the motor again. Started up fine and on the initial run of the morning operated great. Second spot of the day the motor would not heat up past about 80 degrees. Cleaned thermostats again and checked the poppet and cleaned the strainer.

    Next trip out the motor ran great, this time I am seeing a much tighter tolerance on the coolant temps. Heats up to about 135 and cools back to about 113 or so. Settles in about 121-123 or so. Upon takeoff it runs right about 116-121 degrees on plane at all speeds. Never gets above 140 and never gets below 115 at idle. Also seeing about 1.3-1.4 pressure at idle which is slightly lower than before.

    Already planning on changing the water pump but do the coolant temps sound to be in line? Motor runs great 13-15 lbs of pressure mid range and 18-22 lbs WOT.

  2. Member
    Join Date
    Apr 2015
    Location
    ponchatoula la
    Posts
    1,517
    #2
    Sounds like my 250 pro xs

  3. Member
    Join Date
    Jun 2013
    Location
    LONGVIEW TEXAS
    Posts
    14,037
    #3
    just lil low on psi at idle ,not bad though
    .................................................. ...the scariest thing in life is the unknown ...................................

  4. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    95,253
    #4
    Sounds like it's achieving operating temps at idle... which is the requirement. 120 minimum temp at idle under normal conditions.

    On plane temps are going to vary- thermostats are no longer in charge of coolant flow when on plane (they just go along for the ride, more or less... poppet valve is controlling water flow).


    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