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  1. #1

    Default 90 hp Yamaha spark arc problem?

    Have a late 80's 90 Yami that runs good at idle and WOT. When i bring the throttle back down to a low rpm, it runs crappy for a moment and dies. I start it back up again and seems to run fine. I gave it a Seafoam treatment and it seems to run better except for the same problem. One thing i noticed when i had the cowl off, i got a shock when one of the wires arced as i was reaching over it. Could a bad wire or coil be my problem? What else can i check to troubleshoot? Any ideas?

  2. #2
    Lieutenant Junior Grade david_r's Avatar
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    Default Re: 90 hp Yamaha spark arc problem?

    welcome to iboats!!!

    yes a bad wire or coil could be the problem.

    do you have a good blue spark with a good snap?

    the best way to find a bad plug wire without shocking yourself is to start the eng in the dark with the hood off.

    i would lean more towards a loose wire in the remote control box since it only does it when you power down.... a bad coil or plug wire would most likely effect power at a more consistent rate.
    give a man a fish and he will eat for a day...........teach him how to fish and he will sit in a boat and drink beer all day.



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