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  1. #1
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    20 hp electric start conversion

    I recently started to add electric start to my ‘97, 20 hp Merc. I was fortunate to find a local guy that sold me most of the required parts for the conversion. He supplied me with a flywheel from a 2003, 25 hp motor which had the ring gear installed already. I thought I’d just swap flywheels but noticed that the newer flywheel had 4 magnets and my original one had two. I suspect that the extra magnets were to provide extra power output from the stator coil but that’s only a guess.

    Question is, can the 4 magnet flywheel be used on my older motor or will the extra magnets “confuse” or mess up the original switch box / ignition system? I was thinking it may be safer to just swap the ring gear onto my old flywheel.

    Any comments or thoughts would be appreciated. Thx
    Last edited by bosco659; 12-03-2019 at 06:26 PM.

  2. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #2
    Really going to need your serial number, and the Part Number for the flywheel in "question".


    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

  3. Member
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    #3
    Ok will dig up the numbers and post. Thanks.

  4. Member
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    #4
    Flywheel p/n: 258 859232C
    engine s/n: 0G487978
    1997 20ML

  5. Mercury 3L/4 Stroke/Verado Moderator EuropeanAM's Avatar
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    #5
    Appears that flywheel may be from the later serial number group (with an auxillary stator installed). That's about the best I have to offer- I doubt it will post a problem.


    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

  6. Member
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    #6
    Ok thanks. I’ll have to wait for the springtime to test it.