So I recently bought a boat and to my dismay I have a crack in my left
manifold. The engine is 5.7 Merc. I'm hoping that this is the only
thing that I have to replace but time will tell. My question to you
is, should I replace both sides and the risers too? I heard that
exhaust manifolds exposed to salt water can and will deteriorate these
parts and the risers too. I believe I may also have this problem too,
because when taking out the drain plugs in the risers there seemed to
be some grime and build up behind the plugs. Open to any suggestions
that are economic as well a maintaining a well running machine.

Replace your entire exhaust system. It's just part of normal maintenance.
Jim
"397ce" wrote in message
oups.com...
So I recently bought a boat and to my dismay I have a crack in my left
manifold. The engine is 5.7 Merc. I'm hoping that this is the only
thing that I have to replace but time will tell. My question to you
is, should I replace both sides and the risers too? I heard that
exhaust manifolds exposed to salt water can and will deteriorate these
parts and the risers too. I believe I may also have this problem too,
because when taking out the drain plugs in the risers there seemed to
be some grime and build up behind the plugs. Open to any suggestions
that are economic as well a maintaining a well running machine.

Or, you could simply inspect the manifolds and risers very carefully to
determine IF they need replacement. It's very possible that an otherwise
good manifold with a crack could be repaired for a reasonable cost. It's
almost certainly worth checking out.

If you are at all handy removing and inspecting the manifolds and risers
should not present a problem. That should permit a god inspection. If you
need replacements your labor is not wasted and if not you will certainly
KNOW the condition of your system for the cost of gaskets, time, and some
skinned knuckles.

Butch
"JIMinFL" wrote in message
hlink.net...
Replace your entire exhaust system. It's just part of normal maintenance.
Jim
"397ce" wrote in message
oups.com...
So I recently bought a boat and to my dismay I have a crack in my left
manifold. The engine is 5.7 Merc. I'm hoping that this is the only
thing that I have to replace but time will tell. My question to you
is, should I replace both sides and the risers too? I heard that
exhaust manifolds exposed to salt water can and will deteriorate these
parts and the risers too. I believe I may also have this problem too,
because when taking out the drain plugs in the risers there seemed to
be some grime and build up behind the plugs. Open to any suggestions
that are economic as well a maintaining a well running machine.

On Sat, 01 Apr 2006 21:59:28 GMT, "JIMinFL" wrote:

Replace your entire exhaust system. It's just part of normal maintenance.
Jim
"397ce" wrote in message
roups.com...
So I recently bought a boat and to my dismay I have a crack in my left
manifold. The engine is 5.7 Merc. I'm hoping that this is the only
thing that I have to replace but time will tell. My question to you
is, should I replace both sides and the risers too? I heard that
exhaust manifolds exposed to salt water can and will deteriorate these
parts and the risers too. I believe I may also have this problem too,
because when taking out the drain plugs in the risers there seemed to
be some grime and build up behind the plugs. Open to any suggestions
that are economic as well a maintaining a well running machine.



Concur. How old is the boat? I hope the manifold crack is the only problem,
and that the cylinders didn't get filled with water.
--
'Til next time,

John H

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Butch Davis writes:

Or, you could simply inspect the manifolds and risers very carefully
to determine IF they need replacement. It's very possible that an
otherwise good manifold with a crack could be repaired for a
reasonable cost. It's almost certainly worth checking out.

Good advice, but let's don't get the fellow's hopes up that he doesn't need
a complete R+R.

I would try to crank the engine over before I do anything. The manifold
probably cracked due to the water in it freezing (Did someone winterize
the engine and exhaust system?), when that water thaws out it
frequently runs down into the exhaust port, and into the head/cylinder.
At that point your looking at a much bigger problem, so cross your
fingers and crank the engine over to make sure it spins. If it does,
you should be OK. But pull the dip stick as well, to make sure the oil
level isn't way up, indicating water in the oil.