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  1. #1
    Member
    Join Date
    Jan 2008
    Location
    ohio
    Posts
    394

    1998 150 opti Revs on startup only after engine being warm.

    OG681323

    Boat starts and runs fine 95% of time.

    Recently have had following issue.

    After i run around lake and shut down somewhere and sit for a while the engine will rev up at the next startup startup then die.... sometimes it will fire again after a couple tries but normally it will just crank over and not fire. If i let it set for 20 minutes it will normally start really hard after a few tries and blow out a puff of smoke. After 10 seconds of a rough idle or so it back to running fine.......

    Going to take fuel/air pressure tonight but just confuses me on why it only does it after engine is warm. Might not have anything to do with it but seems to always happen in the afternoon when its really hot out....


    I assumed a diaphragm/tracker issue but any other thoughts?

    I'm sure the Mercury Wizard (Don) or Sherm will be along to save the day again!!
    Last edited by bjranger; 07-01-2020 at 01:10 PM.

  2. Member
    Join Date
    Jun 2013
    Location
    LONGVIEW TEXAS
    Posts
    14,040
    #2
    possible TPS faulty, he restin right now
    .................................................. ...the scariest thing in life is the unknown ...................................

  3. Member
    Join Date
    Jan 2008
    Location
    ohio
    Posts
    394
    #3
    Yes he must be taking a long holiday weekend nap ������

  4. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
    Posts
    95,253
    #4
    I wish!

    Good idea to check the Air and Fuel Pressures with GLYCERIN dampened, dual-pressure gauge set.

    Record results for:

    -At idle

    -Under Acceleration

    -5 Seconds after shutdown (then restart)

    -10 seconds after shutdown (then restart)

    -15 seconds after shutdown (then restart).

    Also... HOW FULL is your REMOTE OIL TANK?


    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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