Need help with 1985 90hp mercury

[ther2525]

I have a 90hp mercury first time out this year it ran fine. Now its hard to start and does not want to plane out if anyone else is on it with me. The boat is a 16 foot venture. It has 135psi in all 6 cylinders, I took carbs. off and cleaned them but no help. I am going to change plugs next to see if that helps. Any advice would be appreciated.

 

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Re: Need help with 1985 90hp mercury

Good call on the plugs. Observe the condition of the old ones. They can tell you exactly what each cylinder is doing, and from your discription, you may be down one or two.<br />Let us know what the plugs look like, and what performance changes they give you.<br />If you don't have a spark tester, you can take one of your old plugs and make one, using an alligator clip and a hose clamp,<br /> and check the spark each plug is getting.