Yamaha 85hp outboard ignition issue?

So I have a 2018 Yamaha 85hp outboard (2 stroke), with only 91 hours on it. If you have the engine running, and you pull the spark plug leads off each spark plug, one at a time, the RPM should drop if the engine is running on that cylinder. With that being said, when I pulled the spark plug leads off the middle and bottom plugs, it did that. However, when I pulled the lead off the top plug, the engine actually revved up. This has me totally baffled.

1 Answer

  • Anonymous
    6 months ago
    Favorite Answer

    It may be going into 'limp mode' which increases the revs to avoid stalling. The question is why are you messing about with the engine?

    • Vicente6 months agoReport

      The reason why I messed with the engine is because the engine starting to miss a little, and also not planing (getting full power). I checked the leads on the plug when I was troubleshooting. Came to find out, the fuel pump was leaking.

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