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  1. #1
    Member
    Join Date
    Feb 2020
    Location
    Milledgeville, GA
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    5

    2015 Merc 4 stroke 150 issue

    Serial number- 2B177475.
    So about a month ago I first noticed this issue I had with my motor. I was riding on plane and it was almost if I had hit something, the motor showed some very brief hesitation like it lost power for a second, then went right back on plane and running fine. It happened a few times after that very inconsistently and on some days not at all. So fast forward to about a month after first noticing the problem and still running it, I try to get on plane and immediately bogs down and almost feels like the motor is skipping. The motor is physically shaking so hard that it is concerning. Sometimes I would be able to get up on plane and then the issue returns, the motor starts skipping and shaking and I cannot drive through it. It happened to me 8 times in a row trying to get it on plane and failing every time, after idling all the way back to the boat ramp I tried it one more time and of course, it ran perfectly fine and no complications to it. The strangest part about the whole thing is how inconsistent and random it is, the motor isn't flashing any codes that I can see on my vessel view. I've seen a similar thread else where but it seems like nobody really had a definite answer. I have a video of when it happens when I am on plane but you cant really hear it skipping out but you can see the motor shaking before and as I set it down. Any recommendations would be appreciated. Thanks


  2. Member
    Join Date
    Sep 2017
    Location
    Pryor, OK
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    2,783
    #2
    Someone with actual knowledge will be along soon, but have you checked the fuel rail screens?
    2022 Ranger Z520R, 2022 Mercury 250 ProXS 4s
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  3. Member
    Join Date
    Feb 2020
    Location
    Milledgeville, GA
    Posts
    5
    #3
    Yes, it seems at this point that it is not a fuel related issue

  4. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    95,217
    #4
    I suspect the problem is caused by either a loose connection, a problem in the boat harness, or a keyswitch/lanyard problem.

    Suggested steps:

    -Check the 14 pin connection at the engine and make sure the locking ring is rotated to the FULLY locked position. Disconnect, inspect plugs, and then reconnect while again making sure it is completely locked. See if problem persists.

    -Obtain a Transom-Mounted Keyswitch Harness, plug it in and go run the engine to see if the problem is present (assuming the above did not resolve the problem). This will quickly show whether the problem is INSIDE the cowling, or in the BOAT'S wiring.

    -If problem is still present- check all grounds and harness connections inside cowling. An "On the Water" recording on the G3-2019 Computer Diagnostic System would be most useful at this point.

    * Due to the very abrupt nature I strongly suspect this problem is electrical in nature.


    Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
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  5. Member
    Join Date
    Apr 2019
    Location
    Fbks AK
    Posts
    173
    #5

    Unhappy

    That thing shakes likes somethings loose.... my old 90hp2cyce didnt miss a beat when the lower unit fell clean off at 30mph ....65 miles from anything :(

  6. Member
    Join Date
    Apr 2012
    Location
    Weaubleau MO
    Posts
    1,473
    #6
    Follow DON WEEDS info he is a very good informational person who gives out FREE info on helping people with problems, not many around who will do that especially someone who owns a shop and still helps for free.