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  1. #1
    Cadet
    Join Date
    Jun 2011
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    Default 1971 Mercury 650 Thunderbolt Ignition

    Hi
    My Mercury outboard seems to have some sort of ignition problems:
    Took it out a few days ago and it first started and ran fine. After about 10min. of fishing, we tried to start it again, and barely succeeded. When driving, it runs at about 1/4 of power and leaks fuel badly (you can smell it). After trying to reach the shore like that we moved the throttle lever just a tiny bit from max and back to max again and it started to run fine again and the smell of fuel disappeared as well. After we killed the engine, we couldn't start it again.

    Now I was looking at the distributor cap today and it's definitely moving in both directions quite a bit in relation to the distributor. We tightened the clamp as much as we could, it started moving less but still is moving.

    Now I am not sure if this is normal and would be glad if someone could chime in on this.

    Thanks
    Alex

  2. #2
    Cadet
    Join Date
    Jun 2011
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    Default Re: 1971 Mercury 650 Thunderbolt Ignition

    Amyone?

  3. #3
    Petty Officer 2nd Class
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    Feb 2010
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    Braidwood,il
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    Default Re: 1971 Mercury 650 Thunderbolt Ignition

    yes it is suppose to move that is how it advance's the timing while reving up

  4. #4
    Cadet
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    Default Re: 1971 Mercury 650 Thunderbolt Ignition

    I see, thanks douglas.

    Does anyone have any other clues of what might be the culprit?

    Btw the fuel filter inside is.crystal clear, the filter from the tank is new as well as the hose from fuel tank.

  5. #5
    Petty Officer 2nd Class
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    Feb 2010
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    Braidwood,il
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    Default Re: 1971 Mercury 650 Thunderbolt Ignition

    sounds like a stuck float in the carb, dirity carbs can lead to bad performence, i always check for spark,compression and fuel. Carb kits are cheap so is the fuel pump also how is the wiring on it on my 1971 i change the wires

  6. #6
    Cadet
    Join Date
    Jun 2011
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    Default Re: 1971 Mercury 650 Thunderbolt Ignition

    Just removed the two carbs and they are as clean as new and the float works flawlessly. The needle is very clean as well. Any other suggestions? Btw, I did buy new Sparkplugs because the old ones looked like they were still original, though I haven't started the boat yet with them, because I have to get the carbs back in.

    Any other suggestions guys?

  7. #7
    Lieutenant Junior Grade Wingedwheel's Avatar
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    Jun 2009
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    Michigan
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    Default Re: 1971 Mercury 650 Thunderbolt Ignition

    See if you can start it by spraying fuel into the carbs. If that works, check your lines, bulb and fuel pump.
    The dictionary is the only place that success comes before work.

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