Muffler Replacement

[Capt Happy]

Good Day All,

Reaching out to the community for help in sourcing a st'bd side replacement muffler for our 1997 320 Voyager.

The original muffler was manufactured by Naqualift. This is a four inch, two in, one out horizontal setup. Engines are Crusader 350XL's.
Have reached out to Great Lakes Skipper, Marine Parts Source as well as other distributor's. They are unable to cross reference this it seems.
The Carver part number is 5111701. Any help or advice on where to head next would be greatly appreciated.
Thanks in advance for all replies.
cheers, Capt Happy

[paulr]

I had a muffler blow once because the old exhaust elbow became blocked. The overly hot gases burned out the fiberglass where 4" exhaust tube connected. Once I finally got the muffler out it was a pretty easy repair with a fiberglass kit.
A new muffler of course was not availible.

[Viper]

I'd try to get it repaired first, a fiberglass tech can help with that. You can also try Centek, they may be able to help with an equivalent model...
https://centekmarine.com/markets/recreational/

What's wrong with the existing one? What makes you think it needs to be replaced besides the way it sounds per your other post?

[Capt Happy]

Hi Viper,

There is no apparent damage visible from the outside. The reason we are considering replacing, is due to the very noticeable increased exhaust noise from this side compared to the other. Do you have any experience with the slip in silencers ?

[Viper]

If there's a problem with the muffler, it's rarely apparent externally save for a leak, it's usually due to an internal problem like a broken baffle or the way the muffler's mounted. It's difficult to get the exhaust system on a vessel to sound exactly the same on both sides as there are a lot of variables that affect the final outcome. If all is okay at the muffler and before it, it could be the run from the muffler to the discharge. The other thing you have to consider is not trusting what you hear in a slip as your surroundings will affect the acoustics, and how it sounds depending on where you're standing when you're listening to it. Get in open water and listen to it while standing on your swim platform, even then, depending on your model, whether your discharge is part way in the water or not will affect the sound, one side may sit higher than the other if the boat has a slight list. Is it the exhaust or a vibration you're hearing? Is it due to an engine runnability issue that isn't obvious? So many variables to consider here.

A silencer may quiet things down but you have to wonder if that's just a band-aid fix, if indeed there's a physical problem. Anything you introduce into the exhaust system will contribute to back pressure and can affect engine performance so be sure you're not minimizing one problem but creating another. Is the noise intolerable or is it just annoying you because you know there's a difference? Does anybody else bring it up?

[bud37]

Totally agree with the above.....consider what was said in the other thread about water flow as well, many variables.

Perhaps removing the muffler and inspecting it thoroughly on the inside including hoses etc whilst apart.Root cause is very important to this.

I had a boat that had the exhaust system hung from the above decking but over the years the hangars became broken and had been fooled with by improperly fixing them with strapping. Once I fixed it back to flexible service again ( much like a car exhaust hangar) the noise and vibration subsided considerably. Now this might not be your case but just an illustration.

[Capt Happy]

Thanks all,

I have experimented with shutting one engine and then the other down while comparing them both, away from the dock, on open water and without any outside factors, i:e wind, waves, vessel list. Everything being the same, it is quite a noticeable difference. That being said, while side to at a dock, this becomes even more apparent.

I prefer not to have to purchase a new muffler, so will disassemble and look at the internals. Although if the baffles have failed, not sure if this could be repaired?

The main reason for the post was, the current producers, Centek, Corso, etc are unable to provide a recommended replacement.

I am able to find vertical lift exhaust components from Naqualift, but nothing horizontal. So I was hoping maybe someone had replaced theirs over time and had a source for a new one, if required.

[Viper]

I haven't had an internal muffler failure yet that wasn't repairable.
Check with these salvagers in Florida...
https://www.themarineconnection.net/
https://donsmarinesalvageyard.com/