Dry exhaust system inspection raw water cooled-gctid346308

[Guest]

My boat is going on 8 years, it is trailered, flushed and preserved with salt away every use. What actually fails on the dry exhaust system and if I pull the risers what exactly am I looking for? I have read on some sites where others say to just run them until you see a temp rise that any leakage will be external. Researching replacements it seems there are non except for mercruiser oem dry joint parts. I got 7 years out of my old boat exhaust which was not a dry joint system untill traded for my new 289. How can you tell on the manifold of a dry system if a problem is developing?

tks

Rock

[Guest]

Hi Rock, I m not sure how you check if they need replacing. I have 2004 285 and notice my temp has gone up 7 degrees this past summer going to replace them, everyone tells me it's time. There's a place near me that says he has after market dry joint exhaust coming in, haven't seen them yet. They are supposed to cheaper.

Roger

Narraganset Bay, RI

[Guest]

Roger,

Keep me posted on the after market dry joints. I will probably pull one riser in the next few weeks to see what it looks like inside. The manifold should be sealed (water/exhaust) so unless it eats through I cannot see how to inspect. I know the old manifold trouble spot was the small metal space seperating the water and exhaust and it was easy to see by just pulling a riser. I have been doing alot of research into aluminum for salt water use. Seems like if you use aluminum you need to use annoides and keep up with them. HGE aluminum manifolds (old style) can be used in place of the dry joint you just have to use a taller spacer. There is another company that makes aluminum that is ceramic infused inside and out with a 5 year warranty. If I can get 8-10 years out of dry joint by flushing and using salt away every use I should get that out of aluminum with annoids. The company said the old style manifolds pre 2004 will replace dry joint with a spacer. My dry joints already have a 3 inch spacer I believe. Looks like the ceramic infused alum and merc dry joint are about the same price. The advantage would be easier to install at half the weight and less weight in the aft end of my boat would be a good thing. You would think that since 2003 an after market dry joint would have been made. Maybe they are good for 10 years and just starting to go unlike the old style that were 3-5 years max.

Rock

[Guest]

Hello Rock,

I think I'm at the same point you are. Six years and temp is slowly rising. I am very interested what your inspection reveals. I hope you update this thread after you do your inspection. I can't pull mine as it is still middle of winter here in Northeast.

Thanks,

Tony

[Guest]

Rock

I have talked to the people at Bay Marine store near me. The company supplying them is MalloryMarine.com I still haven't seen them yet. I need 6 inch spacers, said my total cost would be around $1100.00 we will see. According to Mallory web site it's a 2 year parts and labor warrantee.

Roger

[Guest]

http://www.perfprotech.com/

This is who I talked with about replaceing my dry joint with alum ceramic infused ones. They are like the old cast iron version (not dry joint) but with a 5 year warranty and 1/3 the weight. They are about the same price as the Dry Joint replacement from merc. Since I trailer/flush and use salt away every use I would think these would last for many years.

Rock

[Guest]

How about a little advise from you long time boaters out there. I was going to pull one side elbow and riser on my dry exhaust and see what it looked like (even bought the pricey gaskets). Looking at the system and the numerous inspection pipe plugs I decided to pull them first. I have had the boat since new and always keep it in my driveway on a trailer (flushed and preserved with salt away every use). Besides the surface rust I cannot see any rust flaking in any of the passage ways in the water jackets or any type of rust restrictions. I have pulled the elbows on both my old boats that did not have the dry exhaust system and after a few years they had major rust and flaking and restricted passage ways. The Merc parts guy told me they do not sell any where close the amount of dry system replacement parts as the old style. He even said that the insides were ceramic coated, I cannot tell that or maybe that has finally worn away. I think I am just going to leave the system as is for another few years and just make sure I do not have any temp rise. Just because the boat is 7 years old I cannot see replacing any exhaust parts with the just surface rust that I can see inside. What do you think!!!! How many out there have replaced the dry exhaust systems? I also just found out that in 2004 they went from a cold dry system to a warm dry system. The parts guy also said the elbows will go before the manifold. If that is the case it would not matter if it was a full closed cooling system or not when it comes to the riser. Like he said a lot of boats are kept in the water or dry store and those are lucky to get flushed no less have salt away ran thru them.

Rock

[Guest]

Hello Rock

Just helped my friend take off his dry joint exhaust, his boat is a 2004, keep in salt water all season he flushes the system each time he uses it, just with fresh water, they look really good no flaking at all, we are going to reinstall them with new gaskets.

Roger

[Guest]

Roger,

Thanks for posting that, it looks like the new warm dry exhaust system (2004 on up) lasts for quite a few years. Did you notice any ceramic coating inside the the manifold, riser or elbow? When I pulled the inspection plug on the manifolds they were a gray color inside. I do not know if that was the ceramic coating or just a dark appearance from the exhaust. What I could see inside the riser and elbows were just a rust coating with no flaking like your buddys.

I do one thing different when I start my water flushing. An old boat mech swore by this and I figure what the hell, it cannot hurt anything. He said to flush the motor with dish soap like dawn. So I take the salt away flush adapter and fill half way with dawn and run the motor till that is used up. The exhaust dumps foamy water big time, than I fill with salt away and run 1 min while that goes thru the system and than shut down. The old guy said the soap foam will remove any salt or sand deposit build ups and that does make senses since the foaming action might break down the salt deposits. Using just a fresh water flush without a salt block is the problem with cast iron manifolds. Think how long your car block would last if each time you used it, you drained all the water and just left residual water and air in the system. Rust would start to eat the metal just like in our boat engines and manifolds. I am gonna look at maybe using a water based oil like they use in drilling, cutting and lathe work. I would think if I can hook up a big venture suction type flush adapter and add this to my fresh rinse it would coat the internal water passages and keep any rust from occuring better than salt away.

Any body else pull any dry exhaust systems that are over 7 years old apart yet?

Rock

[Guest]

Rock,

If there was ceramic in the manifolds its hard to tell. The interior looked new better than the outside which he is going to clean up and paint. I'm going to take mine off with in the next couple of weeks the only time mine get flushed is at the end of season. If they look good going to put them back. That is a good idea to use dawn and salt off. I need to add a flush system where I dont have to lift motor hatch.

Roger