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  1. #1
    Member AussieJoe's Avatar
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    Mercury Optimax 175 2008 - Smart Craft Alarm

    serial number:
    1B579453 2008 175 Optimax (non pro xs)

    Guys,

    I have an alarm going off at full trim, full noise only when going round a left hand sweeping long corner. The smart craft gauge is telling me its an overlimiter alarm but my revs are still under the 5750rpm, about the 5600 to 5650. I have noticed the engine temp does go up dramatically but water pressure stays the same so I don't think its starving for water(when trimmed down the temp doesn't go up and the overlimiter alarm doesn't go off). I have changed water pump and thermostats recently so they shouldn't be a problem.

    I have taken the boat to the shop and when they plug it in the computer is saying there isn't any faults??

    Does anyone have an suggestion for me? I'm at a loss.

    Any help or suggestions would be great.

    Joe
    Joe Allan
    Nitro Z7 Mercury Optimax 150hp Lowrance Ghost Simrad NSS Evo 3s
    Proudly Supported by: Gamakatsu/Majorcraft/Fuji/Kershaw/Samurai/Atomic

  2. Member
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    #2
    How high does the temp rise? Sounds like you might be losing water flow and causing aeration in a turn. The water pressure would stay the same,maybe.

  3. Member AussieJoe's Avatar
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    #3
    I will slowly rise from around the 118 mark up to about 136 or so and then quickly rise to 160 which is where the alarm goes off, but the fault doesn't say over heat alarm, it says over limiter alarm.....but I know that's way higher temp then it should be, so I think your on the right track with the water flow as I've thought the same. I have removed my transducer as I thought that might be giving it dirty water but that didn't make any change.
    Joe Allan
    Nitro Z7 Mercury Optimax 150hp Lowrance Ghost Simrad NSS Evo 3s
    Proudly Supported by: Gamakatsu/Majorcraft/Fuji/Kershaw/Samurai/Atomic

  4. Member
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    #4
    drop mtr 1/2 in and go run it
    .................................................. ...the scariest thing in life is the unknown ...................................

  5. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #5
    If you have further difficulties, good idea to open a thread in the 2.5L Forum (next one down the list).


    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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  6. Member AussieJoe's Avatar
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    #6
    Thank you
    Joe Allan
    Nitro Z7 Mercury Optimax 150hp Lowrance Ghost Simrad NSS Evo 3s
    Proudly Supported by: Gamakatsu/Majorcraft/Fuji/Kershaw/Samurai/Atomic