Rust on Riser and how difficult to remove 5.0 MPI

If you are going to keep this boat for a while I would strongly recommend upgrading to the dry joint system - the parts would be more expensive and are only available from mercruiser - do a search on here, the benefits have been outlined before.....
 
Smitty, as a side note - fold the rear bench legs and let the bench drop to the floor. Next you can disconnect the gas spring struts from the hatch and then use a rope to tie the hatch open - tie from hatch latch to your ski-tow bar. Dropping the bench to the floor allows the hatch to open a little wider.

When putting the mani's back on, first install two 8" long pieces of 3/8x16 (double check me on the size) threaded rods into two of the holes for the manifold bolts. Then you can much easier slide the mani on. The rods need only be turned in by hand about 5 or 6 threads. Next, install two of the mani bolts and remove the rods.
 
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Thanks Dennis but the actual deck of the boat sits midway over the riser on starboard side. Port side seems to have more clearance where i can pop the gas springs off.
 
smittyasc3 said:
Thanks Dennis but the actual deck of the boat sits midway over the riser on starboard side. Port side seems to have more clearance where i can pop the gas springs off.
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Not about clearance for the manifolds. It's about clearance for your head. Makes moving around and lifting the mani assembly much easier. Only takes about 3 minutes to do this. Make sure you protect the bench against the floor snaps with a towel, if you don't have the carpet in.
 
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ok guys. i have the manifold and riser off....how do i sepearte the 3" extension from the manifold???????
 
Turtlesboat said:
Not so quick. He's got 1+ years to go before he can verify this.
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I'm going to give myself more time then that.

I’m changing my answer from 10 years to 15+ years.

I have no intention to chang my manifolds on my fresh water only boat before the engine is at least 15 years old.

Keep in mind our season is ½ year and I do winterize the engine + store indoor heated.
 
@idindoit - What is a dry joint?

@Smitty - I just took one off my 4.3, and if you tap on the sides of the 3" section, it SHOULD come free.

This rust trail was just a little drip trace last year.
 
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wow. yours are alot worse then mine are! I did tap & tap & tap. have it about 1/4" seperated.
 
@Smitty - Geeze, thanks. These are apparently original from a 2001, salt water. I have checked ebasicpower.com and replacements are 479 + 149 for the 3" spacer. I was wondering what site had the electroplated ones. That seems like a better idea. Note that this just had a little trickle line last year, like the one you can see on my starboard engine in the pic.
 
Try this site... http://www.perfprotech.com/store/default.aspx

@Doug I have to tell you they dont look all that bad inside. I think most of that rust we saw on the pics was just fro the outside of the riser. Inside the manifolds look pretty dry. Just a few drips and very little rust! Ill post pics tomorrow!
 
Ok, I have found some cast (630), powder coated (Need to ask tomorrow if that is inside and out) 779, and electro deposition coated (Inside and out) 789. This is an interesting decision. I am going to go over mine a little better tomorrow and see how they look, but I have a feeling its time to replace.

Mike
 
So here are some pics. And I have to say they really dont look that bad. The manifold looks fine inside and out. So i think I am just going to replace the 3" extension and riser. and all gaskets of course.


View attachment 18649
 
The flanges look virtually new. The insides also looks new. Check them with a straight edge.

If that checks out, I would have no issue reusing them on my boat.

Doug
 
If the manifold looks good, I would re-use that, but replace everything else and go boating. otherwise you'll be doing the same thing at the end of the year.
 
Here's the manifold. I am having a hard time sliding the extension off with the studs still on. I guess I have to try and bust the studs loose. I dont want to pry it for obvious reasons. Any suggestions.

View attachment 18651
 
Take a block of wood and hit the extension on all sides with a hammer. It should break free.

Doug
 
When I took that bottom water fitting off my manifolds, thats when I saw the rust build up. When I compared the new manifolds to the old, I had at least 1/4 inch more inside diameter. And in that fitting itself, the build up of rust/salt or whatever it was, was about 1/8 inch or more around the whole circumference, so I really cleaned the fittings up with wire brushes before re-using them. They came out like brand new.
 
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