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  1. #1

    Default 1981 Mercury 90HP Switchbox Problem?

    The motor is somewhat difficult to start but once running it seems to run ok. However when you put it in gear and advance the throttle it bogs down and seems to be running on 3 cylinders. This continues for several minutes and then it acts like additional cylinders kick in in 3 steps. Since this is a 6 cylinder and it has two switchboxes, I'm thinking one box is bad. Can warming things up affect the box like this? How do I test this? If it needs replacing can you replace just one? Am I looking in the wrong place?

  2. #2
    Seaman Apprentice
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    Default Re: 1981 Mercury 90HP Switchbox Problem?

    Hi,I have a 1980 inline,90 hp. I was told by a mechanic and by the manual that switchboxes can only be tested by a mechanic. I had a simliar problem,when I switched boxes(top to bottom ,bottom to top)it idled better but ran worse .New switchbox fixed it. Also stator wire connections can be loose. Good Luck!

  3. #3

    Default Re: 1981 Mercury 90HP Switchbox Problem?

    I have a 1980-81 inline six mercury outboard that has always been a hard starter but have now lost spark in cyl 1,3,5 moved a trigger lead of of #2 coil and but it on #1 and #1 started sparking so is it my trigger or my stator or my switch box not sure how to tell please need help my mechnic has come up short.


    Naladog

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