My 70 hp Merc has a slight leak

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country cadillac 48

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My 1979 70 hp Mercury, serial #5352752, has developed a water drip out of the gasket between the head, where the plugs are and the block. The Clymer repair manual I have isn't worth too much and I've been trying to find a Mercury manual for this motor, but no luck yet. Is this repair similar to replacing a car head gasket if the head and block are in good shape? These I've done before. Unbolt the head, clean the surfaces,check for flat surfaces, get new gasket and put it back together. Or is there a bunch of other stuff I need to deal with. I really need the right manual.....You folks have been great helping me out and I really appreciate it.................Ray
 
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Laddies

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Re: My 70 hp Merc has a slight leak

It's only a water jacket cover not a head, the biggest problem is not breaking the bolts off. Soak them for a couple of days with a good penetrate, use heat if you have a torch and a lot of care. Some people like to use a impact wrench others just use a socket, which ever you use take your time.
 
C

country cadillac 48

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Re: My 70 hp Merc has a slight leak

Thanks Laddies and carholme you've done it again.....Exactly what I need to know on both accounts....I do have a torch and a lot of patience. I just borrowed a compression gauge and I'm getting 137 on #1, 117 on #2 and 136 on #3. The water leak is even with #2 cyl, would that be related to low compression on that cylinder ?? Or I"ll need to wait till I get a look see when it's apart............Ray
 
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Laddies

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Re: My 70 hp Merc has a slight leak

It is not related to engine compression, you may have a sticking ring and running some powertune might help.
 
C

country cadillac 48

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Re: My 70 hp Merc has a slight leak

I have just added some Seafoam the other day and haven't run the motor since, is that a type of powertune or is this a specific product ?
 
C

country cadillac 48

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Re: My 70 hp Merc has a slight leak

Thanks again for everything and hopefully the Seafoam will get some of the compression back and the PB Blaster will loosen up the bolts on the block cover.........take care and I will definitely talk to you all again.....................Ray
 
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