mission sea ray fix up

[hobby10k]

Ok. Time to fix up old sea ray instead of buying a newer boat (darn)

Going to go through the engine to make sure I don't have to worry about anything. As well as doing a couple performance bolt on upgrades.

First question, I am reading about manifold and risers should be replaced often it seems. My question is, does this apply to a closed cooling system? It's early 90s 5.7 mercruiser. I'd rather not spend the money if I don't have to, or even clean it up and keep using it if I can. But if need be I'll replace what I have to.

Second question. Which bra,d of manifolds and risers to get and what to avoid? And where is the least expensive place to get the parts?

Thanks in advance.

 

[Bondo]

Ayuh,..... Do ya run yer boat in Freshwater, or in the Brine,..??..??

Manifolds, 'n risers will last a lifetime in freshwater,...

 

[tpenfield]

Post a few pictures of the SeaRay when you can . . .

As Bondo says, manifold replacement is mainly for us salties . . . not freshies. Also, if you have closed cooling (in salt), it would depend on if the closed cooling were a 'half' system or a 'full' system. A half system would only run the closed cooling through the engine block . . . a full system does both block and manifolds, running the outside water only through the elbows.

Good manifold brands are Mercruiser, Osco, Barr . . . GLM are not so good.

 

[hobby10k]

Pulled the risers and manifolds off, and looks like both riser gaskets had a slight weeping leak, and some corrosion is built up on the exhaust ports. I shined a light into the exhaust ports and doesn't look like water got into the cylinders, However I think I should probably just pull the heads to make sure rust didn't build up on the cylinder walls. Maybe while I am at it I can throw some Vortec heads on. Or I could just spray some penetrating oil into the cylinders and let the oil sit in there for a while. But probably just better to pull the heads and see whats up.

as far as the manifold and risers go. I don't know the shape of them. there is corrosion built up, so most likely I will probably just replace them. I am going to run them down to the local boat shop and see what he thinks before I do that. I'd hate to spend a bunch of money if I don't have to.

 

[Chris1956]

Normally the risers rust out first, in my experience. Specifically the rearmost part of the risers, where the cooling water runs down the riser, and then mixes with the exhaust as it enters the elbow.

If the risers and manifolds look OK, you can use some emery cloth and a piece of plate glass to clean up the manifold - to- riser gasket surface. Use the grey Mercruiser gaskets for the best seal. I presume you are running in fresh water? If not, the exhaust components should have been replaced already, and are about due to be replaced again.

 

[hobby10k]

checking out some riser manifold kits. Are the aluminum ones good, not good?

 

[hobby10k]

funny how a tune up, light fix up and clean up turns into a tear down and major job lol.