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  1. #1
    Member
    Join Date
    Jan 2009
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    Fredericksburg, VA
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    523

    Fuel Octane Question 2003 Mercury 225x

    On the lake a fish I have always been able to get 93 octane ethanol free fuel. Went to gas the boat up this week and was informed that 90 octane is all they have for the foreseeable future. My question should I run some kind of octane booster or bite the Bullet and switch to 93 gas with ethanol. Any help would be appreciated.
    2003- Bullet 20XD w/Promax 225X

  2. Member
    Join Date
    Aug 2008
    Location
    Bedford, Indiana
    Posts
    25
    #2
    On my 2002 225X, I run 87 then add Aces Octane Boost at the 1 oz / 6 gallon ratio. Been doing this for many years.

    Hydromotive is my Aces source.

  3. Member rocketman6965's Avatar
    Join Date
    Mar 2014
    Location
    Lake Worth, FL
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    1,612
    #3
    I run 93 ethanol all the time. Use Marine Stabil and Lucas Fuel treatment. Good performance and very clean prop

    Joe Perez
    Boatless white trash

  4. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
    Join Date
    Apr 2008
    Location
    Greenville, SC (US)
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    95,137
    #4
    If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info when posting. Thanks!

    Really need a high-test fuel source for this engine (would absolutely no run ANYTHING below a bare minimum 91 octane, based on your description of what the engine is).


    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

  5. Member
    Join Date
    Jun 2004
    Location
    rockville
    Posts
    385
    #5
    93 ethonal is all I've ever run in mine, and never had a problem.