Yamaha 90 hp 2 stroke loses power

SKG

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Sep 14, 2015
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1997 Yamaha 90 hp 2 stroke (no oil injection) loses power intermittently. I have noticed it happens mostly after hitting a wake or some rough water. I stop the boat and turn off engine. Then immediately start engine (no problem starting at all) then take off and achieve top speed with no issues. I also have fished all day and it hasnt happened at all. Carbs look clean as do fuel filter, plugs. Fuel does not appear to contain water. Burning ethanol free fuel.
 

robert graham

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Apr 16, 2009
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Mine is a 1999 C90 very similar to yours and the one time I had a wake related issue it turned out to be the wiring under the console was bouncing around when I hit the wake....while you're running try jiggling those wires with your hand to try and locate a loose or bad connection....I've since used some tie wraps/zip ties to hold the wiring snug....
 

SKG

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Joined
Sep 14, 2015
Messages
2
Mine is a 1999 C90 very similar to yours and the one time I had a wake related issue it turned out to be the wiring under the console was bouncing around when I hit the wake....while you're running try jiggling those wires with your hand to try and locate a loose or bad connection....I've since used some tie wraps/zip ties to hold the wiring snug....

Thanks for the suggestion. I'll check it out the weekend!
 

robert graham

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Joined
Apr 16, 2009
Messages
6,908
My issue was just a bit of corrosion on the tip of in-line fuses....clean, Polish and grease these....
 
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