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  1. #1
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    150 Optimax - 2010 - Not Firing

    Hello, I recently bought a 2010 Nitro Z-7 with a 2010 150 Optimax. It has an original 94 hours on it.

    The serial # 1B792084.
    Make and Model #MROB/1150D73.

    The boat had blown lower unit and had sat for awhile when I bought it, and put a new lower on it, and it ran great great for 8 or so fishing trips after the lower unit was replaced. I had no known issues.

    I was out fishing this past weekend (in a tournament), and started noticing that as I trimmed it up the motor, it would almost bog down and only turn 4200 rpms, then wouldn't get back up to speed, and stay at 4200 rpms.

    It did that for 4 or 5 times going from spot to spot, then went to start it up the next time and it would only crank, but wouldn't fire over.. I tried for quite a awhile to get it to fire and I never could. I had to trolling motor to a ramp and load the boat.

    The next day, I tried to fire it over in my shop, and sure enough, it fired right over.. I then, took it down to the boat ramp, and put it on the water and it fired over. I rev'ed it a few times, then turned the key off. I tried starting it again, and then the same problem as before, it would only crank, but wouldn't fire over...

    I pulled the boat out of the water, let it sit for 10 minutes or so, then turned the key, and it fired right over. Then, I did the same thing as above. Backed the boat down into the water, started it and it fired over, rev'ed it a few times, let it idle, then turned the key off. Then went to start it up again, and it just cranked and wouldn't fire....

    Any clue where I should start? Anybody ever heard of this?

    Thanks,

  2. Member
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    #2
    possible low voltage at battery weak or bad batt
    .................................................. ...the scariest thing in life is the unknown ...................................

  3. Member
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    #3
    Thanks for the feedback.

    It is a brand new battery with 845 marine cranking amps. I haven't had any problems like that before. Could it randomly start doing that after it has worked fine all the trips before?

    I will try a different battery with 1,000 or more c.c.a. and see if that makes any difference.

    Thank you for the feedback!

  4. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #4
    Quote Originally Posted by gareshady View Post
    Thanks for the feedback.

    It is a brand new battery with 845 marine cranking amps. I haven't had any problems like that before. Could it randomly start doing that after it has worked fine all the trips before?

    I will try a different battery with 1,000 or more c.c.a. and see if that makes any difference.

    Thank you for the feedback!

    Definitely need more battery than you have, even fully-charged the one that was in it is really shy of the engine-only requirements.

    950+ CCA, and make sure the alternator is charging (battery voltage should increase after you start the engine, testing at the battery with a DVOM).


    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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  5. Member
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    #5
    ***Update***

    I did go buy a brand new battery with 1,000 MCA. This did not fix the issue.

    The motor still DOES NOT start when it is in the water. It will just turn, but it WILL NOT FIRE over.

    It will turn, fire, and run just fine when it is OUT of the water, but it WILL NOT IN FIRE over when it is in the water.

    What should I look into next??? Any other ideas?

  6. Member
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    #6
    put it in water test for spark on all 6
    .................................................. ...the scariest thing in life is the unknown ...................................

  7. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #7
    Quote Originally Posted by gareshady View Post
    ***Update***

    I did go buy a brand new battery with 1,000 MCA. This did not fix the issue.

    The motor still DOES NOT start when it is in the water. It will just turn, but it WILL NOT FIRE over.

    It will turn, fire, and run just fine when it is OUT of the water, but it WILL NOT IN FIRE over when it is in the water.

    What should I look into next??? Any other ideas?

    1000 MCA is absolutely the bare minimum for the ENGINE ALONE. Simply not going to cut it. This is why you see the recommendation in Post #4:

    Quote Originally Posted by EuropeanAM
    950+ CCA, and make sure the alternator is charging (battery voltage should increase after you start the engine, testing at the battery with a DVOM).

    As Joe suggested- it's time to do a Spark Test when it's in the water.


    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

  8. Member
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    #8
    I bought 6 new plugs and installed them, and we did a spark test... Everything seemed to check out..

    Still having the same issue.. It will fire over after it has set awhile. But, after 3-4 times of it firing over. It will not fire, and just turn.

    I have read a few blogs with similar issues about a high pressure grommet/seal not keeping pressure?? Idk though.

    Here was the blog I read... Seems similar to my issue. http://www.bbcboards.net/showthread.php?t=529048


    What do you all think I should try next?

  9. Member
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    #9
    procede to fuel psi tests
    .................................................. ...the scariest thing in life is the unknown ...................................

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