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  1. #1
    Cadet
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    Dec 2009
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    Default Mercury Optimax Stalls at high RPM

    HI,
    I have a pair of 2001 mercury optimax 150hp on a 25' footer. Last time i went out one of the engines was running perfect at low rpms (uder 2000rpms) but everytime i would go over 2K rpms it will run fine for about 15 seconds and then stall and die. You can crank right back up without a problem and it will idle, but at this point you can open wide throttle and rpms won't go up past 1500. if you let it idle for 5-10 minutes, it will work again for another 15 seconds or so. Im guessig its getting flooded with gas, but i really don't know where to start looking. Any help will be appreciated. Thank you.

  2. #2
    Cadet
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    Dec 2009
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    Default Re: Mercury Optimax Stalls at high RPM

    Also, the temperature stays cold, there are no beeps or any other indications that something is wrong...

  3. #3
    Ensign
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    Oct 2010
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    South Florida
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    923

    Default Re: Mercury Optimax Stalls at high RPM

    What serial number?
    DO YOU HAVE: GOOD COMPRESSION, PROPERLY TIMED SPARK, PROPER FUEL AIR MIXTURE?

  4. #4
    Petty Officer 1st Class
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    Apr 2011
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    SW FL
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    Default Re: Mercury Optimax Stalls at high RPM

    From your discription it sounds like the VST tank
    is running out of gas.
    maybe filters, primer bulb, anti-siphon valve,
    Fuel line coming apart inside, bad lift pump,
    Plugged VST filter,
    Install fuel pressure gauge and watch
    for lost pressure.

  5. #5
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    Default Re: Mercury Optimax Stalls at high RPM

    Duplicate the secenario again and drain the VST into a graduated cylinder and record amount, then pump the primer bulb until slight pressure is felt and drain into same container. If your amounts vary you could have possible fuel restriction/lift pump problem, if they pretty much equal I would suspect the low pressure fuel pump. Are you the orignial owner? If you are, did you receive a letter about direct injector recall as per service bulletin 2001-01.
    DO YOU HAVE: GOOD COMPRESSION, PROPERLY TIMED SPARK, PROPER FUEL AIR MIXTURE?

  6. #6
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    Default Re: Mercury Optimax Stalls at high RPM

    Quote Originally Posted by edgpr View Post
    Also, the temperature stays cold, there are no beeps or any other indications that something is wrong...
    What temperature is it reading?
    DO YOU HAVE: GOOD COMPRESSION, PROPERLY TIMED SPARK, PROPER FUEL AIR MIXTURE?

  7. #7
    Ensign
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    Feb 2011
    Location
    Sydney
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    968

    Default Re: Mercury Optimax Stalls at high RPM

    If you have a manual I would be checking the EFI system first.Could also be ignition/ timing related.

  8. #8
    Cadet
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    Dec 2009
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    24

    Default Re: Mercury Optimax Stalls at high RPM

    Quote Originally Posted by jeffersondodson561 View Post
    Duplicate the secenario again and drain the VST into a graduated cylinder and record amount, then pump the primer bulb until slight pressure is felt and drain into same container. If your amounts vary you could have possible fuel restriction/lift pump problem, if they pretty much equal I would suspect the low pressure fuel pump. Are you the orignial owner? If you are, did you receive a letter about direct injector recall as per service bulletin 2001-01.
    No, im not the original owner. I bought it about a month ago so im not sure about the recall.

  9. #9
    Cadet
    Join Date
    Dec 2009
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    Default Re: Mercury Optimax Stalls at high RPM

    Quote Originally Posted by jeffersondodson561 View Post
    What temperature is it reading?
    It's cold, the needle is all the way at the bottom of the gauge.

    Quote Originally Posted by jeffersondodson561 View Post
    Duplicate the secenario again and drain the VST into a graduated cylinder and record amount, then pump the primer bulb until slight pressure is felt and drain into same container. If your amounts vary you could have possible fuel restriction/lift pump problem, if they pretty much equal I would suspect the low pressure fuel pump. Are you the orignial owner? If you are, did you receive a letter about direct injector recall as per service bulletin 2001-01.
    No, im not the original owner so im not sure about the recall.

  10. #10
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    Oct 2010
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    South Florida
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    Default Re: Mercury Optimax Stalls at high RPM

    If problem persists, and you can not figure it out, may want to look into it. Take it to a dealer and they can determine whether it has been done by looking at the injectors, serial number, or Mercnet. I think they have to call tech service to get approval. Verify temp at Tstat with pyrometer.
    DO YOU HAVE: GOOD COMPRESSION, PROPERLY TIMED SPARK, PROPER FUEL AIR MIXTURE?

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