1984 mercury gets water in #6 cyl in water, not on muffs.

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larboc

Seaman
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Jul 26, 2001
Messages
61
Going to look at a motor tommorow for the project boat. Says it runs great on the muffs out of water, but when in the water it gets water into the #6 cylinder. I have a theory, any guesses? o, all cyls have good/same compression.
 
C

Chris1956

Supreme Mariner
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Mar 25, 2004
Messages
27,149
Re: 1984 mercury gets water in #6 cyl in water, not on muffs.

It is likely lower crank seals. It could also be inner exhaust cover leak or exhaust baffle is perforated by number 5 or 6.
 
L

larboc

Seaman
Joined
Jul 26, 2001
Messages
61
Re: 1984 mercury gets water in #6 cyl in water, not on muffs.

well, i bought the thing for $350. hopefully it won't be too bad. I was thinking lower crank seal too. Read about the exhaust baffle problem as well. The PO already took the water cover off so that has to be re sealed anyway, but he said it was misfiring so i'd guess it wasn't the cover.

While its already kind of apart I think I will just pull the power head and do upper and lower crank seals, and exhaust baffle gaskets.

Any other things do change/clean with the power head out?
 
T

thefairlaneman

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Re: 1984 mercury gets water in #6 cyl in water, not on muffs.

What are the results from the compression test on number 6?
 
L

larboc

Seaman
Joined
Jul 26, 2001
Messages
61
Re: 1984 mercury gets water in #6 cyl in water, not on muffs.

He didn't remember the numbers when he did the test, he just remembered that they were all even. I know, as a snowmobile mechanic that's what I was worried about if it was the crank seal. Dragging along a lean cylinder for any length of time could be very bad. Hopefully the water would have cooled everything off enough so that it's alright. I won't know till I get it apart. Sure as heck can't see into the #6 plug hole.
 
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