1995 SN exhaust mod?

[Erikgundy98]

I have seen (and read) how people fix this fiberglass exhaust on a 1995 SN, but then I see others who have the exhaust going into a box (muffler) back under the back seat.

I wonder how many of you have done each, or if any of you thought of one, and then did the other. Or, if after changing, did you wish you hadnt.

I also got good advice on the fresh air exhaust, but thats on the outside of the boat. Figure they could also mod up a stainless option on the inside, but I wonder if any of you guys with a shop and welding skills built your own option when you had this problem.

Apparently it was a backfire when my brother owned the boat. Now I am rehabbing the boat back to life, and this is #1 on my list.





I know how to fiberglass, and also have access to a shop and can fab up something... I just wonder what advice is out there for someone who is thinking about both directions and is new to the SN community.

Thanks! Erik

[NautiqueJeff]

The Hull Hugger mufflers you're describing were stock on the later Nautiques. They probably wouldn't fit yours.

With the extent of the damage there, you're better off just replacing your existing Inverta-Flo.

https://www.nautiqueparts.com/produc...nautique-1995/

Use Discount Code PND for 10% off.

[Stevemo14]

I'm pretty sure Fresh Air Exhaust makes a stainless muffler for your boat. I would contact them.

[Jonny Quest]

I had an Inverta-Flow muffler on my 1994 Ski Nautique and it blew out like yours. I paid over $500 for a replacement. If I had to re-do everything, I would NOT go with another Inverta-Flow. Instead, I would go with straight pipes into a “Y” connection and delete the muffler. I have been in several Ski Nautiques with no muffler and found the exhaust nose level acceptable.

Centek Marine makes mufflers and fittings. Look at this Y fitting

https://www.centekmarine.com/product...4-wye-fitting/

JQ

[Erikgundy98]

Thanks for all responses! I have young kids, so I see a muffler as an advantage, but can I ask a few questions I’m having?

1- why fiberglass? What was the advantage of this design? Even the Y JQ posted is fiberglass. Curious why.
2- could this (Inverta-flo) design be made of stainless or aluminum? (Has anyone done this?)

thanks
erik

[Jonny Quest]

Take your Inverta-Flow to a fiberglass shop and see if they will repair it. Should be less than $600 for a new one.

JQ

[mzimmer75]

I had a problem with muffler on my 97 SN. I didn’t get all the water out of it one winter and it froze. The ice cracked the muffler on top and knocked a baffle out. My damage was not nearly as serious as the OP's. I cut open the muffler, pulled the baffle and fiberglassed a patch. Sprayed it with black paint. Good as new, or so I thought. Until I ran the boat and realized it was louder than before. I was disappointed with the noise. I never did anything about it but I was always disappointed in myself for not repairing the baffle. Based on my experience, I would not do anything that makes your exhaust louder. IMO, you will regret it. Unless you are looking for “Donzi mode”.

[SilentSeven]

....
1- why fiberglass? What was the advantage of this design? Even the Y JQ posted is fiberglass. Curious why.

Total speculation but this would be my guess.

1 - less heat transfer with fiberglass
2 - no corrosion issues from the wet exhaust
3 - easy to make custom shapes that fit in tight places
4 - lighter

In the end, a fiberglass muffler is likely less costly than an equivalent muffler made from stainless steel and works just was well.

[gary s]

Here is a email I sent to Centex a number of years ago. If yours froze and broke you have other problems....

Gentlemen- I have a 1995 Correct Craft Nautique Super Sport V Drive equipped with a Pleasurecraft 351 GT40 Ford and an Invertflo muffler. On the Correct Craft Fan forum it was suggested that water is retained in the muffler after shut down and to avoid freeze damage when winterizing that you should suck antifreeze thru the system so that it goes thru the muffler too. Now I'm worried as I have for the 2 years I have owned it, just drained the system and poured antifreeze into the engine and drive,not worrying about the muffler as I assumed it drained at shutoff. There is nothing about this in the owners manual and naturally nothing in the PCM manual about the exhaust. Looking forward to your thoughts-

Good morning Gary,

You are correct, by design, we have always included a drain hole in the outlet pipe of the muffler in order to drain water when the engine shuts down. However, a very smalll amount of water will remain inside of the muffler. This small amount of water will not pose a problem if it were to freeze. If the muffler was full of water, then you would need to worry about getting antifreeze into the muffler. We also include drain screws in the mufflers to drain water as well.

Let me know if you have any other questions.

Regards,

Bert Browning

Centek Industries, Inc.

Manager, Product Design & Engineering

Mechanical Engineer

[mzimmer75]

Interesting info. As I don’t own the boat anymore, I’m not going to worry about if it was or wasn’t freeze damage. The point of my post, was that a modified muffler changed the sound level of the boat. I wasn’t happy about that.

[Jonny Quest]

Nothing quite like the throaty battle-cry of a V-8 engine at full throttle. I "get it" that quiet can sometimes be better...but your Nautique growling is a very cool sound. GO LOUD!

[gary s]

Yea companies don't put extra parts in stuff just to do it- there was a reason those baffles were put in. FYI if you think your 97 was loud don't ever buy a Correct Craft with a Holman Moody in it,you won't like the noise they make either

[Erikgundy98]

Do any of you know of anyone selling (or who replaced the InvertaFlo with one of these straight options) who might sell me their InvertaFlo?

Im now kind of concerned about recreating the “bubble” that was blown to pieces, on top of the baffle in the muffler. Has anyone ever done this? Any success or advice?
thanks!