86 Mercury 90 Inline 6 bogs down in gear only in the water

dawg_nail

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Joined
Mar 10, 2003
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5
My outboard has been running great. I took it out the other day and the starter messed up. The gear on the end was stripped. I fixed this and now have a new problem. The engine runs fine on land with the water hose connected. I can put it in gear and rev it up. It starts easy etc.. When I put it in the water and put it in gear it doesn't have any power. It just barely runs. I take it out of gear it revs up fine. I have cleaned the cards, checked compression, all so far is good. Any suggestions.
 
D

DJ

Guest
Re: 86 Mercury 90 Inline 6 bogs down in gear only in the water

dawg,<br /><br />What about spark?<br /><br />That cooked starter may have caused something else to fry.<br /><br />A 2-stroke outboard will happily rev up, out of the water, on only a couple of cylinders.
 

dawg_nail

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Re: 86 Mercury 90 Inline 6 bogs down in gear only in the water

I havn't yet tested the spark. I guess that is the next step.
 

12Footer

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Joined
Mar 25, 2001
Messages
8,217
Re: 86 Mercury 90 Inline 6 bogs down in gear only in the water

Welcome to iboats, Dawgnail.<br />Symptoms sound like missing cylinder. If the symptoms surfaced after replacing the starter, I would highly suspect a loose or corroded connection at the switchbox. Take then off one at a time, polish the lug and, lug nut and terminal of each one shiny. <br />A dremmel-style drill (cordless more convienient) with a brass or steel rotary wire brush attachment does a pretty and fast job of it.<br />I would replace the plugs also, if they have over 80hours on them.
 

dawg_nail

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Re: 86 Mercury 90 Inline 6 bogs down in gear only in the water

Thanks 12Footer I will try your suggestion.
 

dawg_nail

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Re: 86 Mercury 90 Inline 6 bogs down in gear only in the water

After checking there is no fire on cylinders 2,4,6.
 
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