Need to change riser with manifold?

[TheRussian]

Hello,

I am planning to replace the port side exhaust manifold on my '93 4.3LX due to a small crack that I noticed last season. I had no issues with it last year, which was my first year with the boat. I assume that the crack is due to improper winterization by previous owner. The oil was clear when I winterized it last fall.

My question is: will I need to change the riser along with the manifold? This will double my expense, and although I am very familiar with the BOAT acronym my wife would be a lot happier if I can keep the cost down (I don't think she cares for my boat...!).

Thanks!

 

[Silverton34c]

Re: Need to change riser with manifold?

hello,

i am planning to replace the port side exhaust manifold on my '93 4.3lx due to a small crack that i noticed last season. I had no issues with it last year, which was my first year with the boat. I assume that the crack is due to improper winterization by previous owner. The oil was clear when i winterized it last fall.

My question is: Will i need to change the riser along with the manifold? This will double my expense, and although i am very familiar with the boat acronym my wife would be a lot happier if i can keep the cost down (i don't think she cares for my boat...!).

Thanks!

Do replace the gasket between the manifold and riser


noooooooooooooooooo!

 

[tazrig]

Re: Need to change riser with manifold?

Also manifolds as with risers should always be replaced in pairs (so the engine continues to get cooled evenly) meaning you should replace the other manifold and gaskets but can leave the risers alone assuming you inspect them and they are clean and the walls that separate the water from the exhaust aren't rotted out. Keep in mind if the manifolds and risers are original to the engine they are 10 years old and should be replaced anyway as the average life expectancy of both is roughly 5 years. If you wait until they let go on their own... water will go into your engine and you will end up with pretty severe internal damage.

 

[Bondo]

Re: Need to change riser with manifold?

Hello,

I am planning to replace the port side exhaust manifold on my '93 4.3LX due to a small crack that I noticed last season. I had no issues with it last year, which was my first year with the boat. I assume that the crack is due to improper winterization by previous owner. The oil was clear when I winterized it last fall.

My question is: will I need to change the riser along with the manifold? This will double my expense, and although I am very familiar with the BOAT acronym my wife would be a lot happier if I can keep the cost down (I don't think she cares for my boat...!).

Thanks!

Ayuh,.... Ya gotta take it Off, Clean it, Then evaluate whether it's got life in it, or it's an anchor,...

If it ain't rotted out,... Sure, Reuse it,...

Use the Merc carbon metallic gaskets for 'em,... Well worth it, 'n Miles ahead of the green paper ones,...

 

[TheRussian]

Re: Need to change riser with manifold?

Would I be able to withhold changing the other manifold if it is not cracked until a later date? Or is it critical to replace the manifolds on both sides at the same time?

Also, are aftermarket manifolds OK to use of do I need genuine Merc parts?

 

[xadiohead]

Re: Need to change riser with manifold?

Would I be able to withhold changing the other manifold if it is not cracked until a later date? Or is it critical to replace the manifolds on both sides at the same time?

Also, are aftermarket manifolds OK to use of do I need genuine Merc parts?

If they are both old, then it is definitely advised to replace them both together but I don't think it is "critical". You can usually get a better deal in pairs though.

Aftermarket is fine, just do not buy the cheap GLM brand. I don't have experience with them, but read a lot of bad things about them. I went with Sierra off of ebay recently and they seem good.

 

[achris]

Re: Need to change riser with manifold?

If the reason for changing is not age related, you are fine to change just one side. Same goes with the elbow (you are calling 'riser') as long as it's in good enough condition to continue service, by all means reuse it... As already said, use new OEM gaskets....

As far as the best brands... I use this list.
1. OEM
2. OEM
3. OEM
4.
5.
6.
7.
8. Barrs or Osco
.
.
.

49. Sierra
.
.
.
.
1283. GLM

HTH.

Chris.....

 

[TheRussian]

Re: Need to change riser with manifold?

How about Teleflex manifold? I found "Teleflex Marine 18-1952-1 Manifold" online that appears to be a good price.

 

[Bondo]

Re: Need to change riser with manifold?

How about Teleflex manifold? I found "Teleflex Marine 18-1952-1 Manifold" online that appears to be a good price.

Ayuh,.... Never heard of such,....

Teleflex is known for helms, controls, 'n cables,....

The part number looks Sierra,...
Which should be available, Right here at iboats,.....

 

[TheRussian]

Re: Need to change riser with manifold?

So... I should NOT use the gaskets that are supplied with the Sierra manifolds? I'm having a hard time finding anything other than Sierra out there.

 

[Bondo]

Re: Need to change riser with manifold?

So... I should NOT use the gaskets that are supplied with the Sierra manifolds? I'm having a hard time finding anything other than Sierra out there.

Ayuh,.... I don't like the green paper gaskets,....

I like the carbon metallic Mercruiser gaskets, on Dry, from a Mercruiser Dealer myself,...

 

[tazrig]

Re: Need to change riser with manifold?

As Bondo mentioned you can get the gaskets from any mercruiser dealer. The difference between OEM (mercruiser) and other brands is that the casting is of a higher quality and also the thickness of the walls between the exhaust and the water jacket are thicker. Both will lead to longer life and safer to use for the engine. (less chance of cracking, leaking etc.) If it is a matter of strict economics then buy what you have to... just know that in most cases going with OEM parts is the best way to go. They are engineered to a higher standard, better quality and will provide you with a longer and safer time out on the water.

 

[TheRussian]

Re: Need to change riser with manifold?

I will check for gaskets at a local dealer. I will probably end up going with Sierra for the manifold. Thanks.