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  1. #1

    Default 1977 OMC 235 HP 351W Ballast Resistor Replacement

    The ballast resistor for my engine is cracked and smokes. I found the Evinruide part number for it as 0981654 2.0 Ohm for $70+. Can I just use an autozone auto equivalent for $8? It just cuts voltage to the coil, I just dont see how the Evinrude version could be that much different from an automotive equivalent beside physical mounting. As long as it has the same resistance rating, wouldnt any one work? Any opinions would be greatly appreciated!

  2. #2
    Rear Admiral Howard Sterndrive's Avatar
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    Default Re: 1977 OMC 235 HP 351W Ballast Resistor Replacement

    I've used an automotive one before and it worked fine.
    Another option is to just change to a coil that doesn't require the resistor and feed it the full 12V.
    Baba-buoy.

  3. #3

    Default Re: 1977 OMC 235 HP 351W Ballast Resistor Replacement

    Great idea! Thanks!

  4. #4
    Supreme Mariner Boomyal's Avatar
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    Default Re: 1977 OMC 235 HP 351W Ballast Resistor Replacement

    Better yet, switch to a Pertronix II ignitor and a Pertronix Flame Thrower coil and you won't need the ballast resistor.

  5. #5
    Cadet
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    Default Re: 1977 OMC 235 HP 351W Ballast Resistor Replacement

    Quote Originally Posted by Boomyal View Post
    Better yet, switch to a Pertronix II ignitor and a Pertronix Flame Thrower coil and you won't need the ballast resistor.

    I'm not sure if this is true but I was told if you have an external resistor you're motor is wired for that style and you can't interchange?

    For example my inline 6 has a 2ohm external resistor and due to that I can't put an electronic ignition upgrade. I was told I'm doomed to that set up? does that make sense?

  6. #6
    Senior Chief Petty Officer Levinz11's Avatar
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    Default Re: 1977 OMC 235 HP 351W Ballast Resistor Replacement

    Quote Originally Posted by monster91 View Post
    I'm not sure if this is true but I was told if you have an external resistor you're motor is wired for that style and you can't interchange?

    For example my inline 6 has a 2ohm external resistor and due to that I can't put an electronic ignition upgrade. I was told I'm doomed to that set up? does that make sense?
    It makes sense, but whoever told you that is wrong.

    The resistor/resistor wire is usually "in" the harness. So to use 12V coil Like the Pertronix you wire it yourself.
    Quote Originally Posted by Bob's Garage View Post
    On the plus side, I don't know what I talking about.
    1988 Phantom 190 4.3 OMC Cobra
    1995 Sea-Doo XP 717

  7. #7
    Supreme Mariner Boomyal's Avatar
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    Default Re: 1977 OMC 235 HP 351W Ballast Resistor Replacement

    Quote Originally Posted by Levinz11 View Post
    It makes sense, but whoever told you that is wrong.

    The resistor/resistor wire is usually "in" the harness. .....
    While this is true for, I guess, most GM motors, the Ford OMC used a kind of ceramic potted external resistor. It was mounted on the motor and very easy to bypass, and as in my case, remove and toss.

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