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I have a 1985 Johnson 140HP V4. Has always ran great until last week. Had it running at 3/4 throttle for about 30 minutes then it was like 2 of the cylinders cut out for 2 seconds "lost lots of power", then fine for a couple minutes, then cut out for 2 seconds,etc. happened several times. I stopped, check spark plugs and wire connections. Everything seemed fine. Started up about an hour later to go and it ran fine for 30 minutes, then did the same thing off and on. Very hard to diagnose because it happens very quickly and only after running at higher speeds for 30 minutes. I'm guessing electrical. Maybe a coil? Any suggestions