Invertaflow Muffler on ’94 Sport Nautique
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=5833
Printed Date: April-27-2024 at 9:53am
Topic: Invertaflow Muffler on ’94 Sport Nautique
Posted By: jameski
Subject: Invertaflow Muffler on ’94 Sport Nautique
Date Posted: February-25-2007 at 9:54pm
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I removed my invertaflow today to do a little fibergla$$ repair on one of the inlets. I noticed the sound of something moving around inside. Is this normal? I tried reaching inside and I could barely feel something at the outlet. I'm guessing it is some kind of check valve that prevents water from back washing into the manifolds. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Replies:
Posted By: Guests
Date Posted: February-26-2007 at 5:56pm
| hmmm.if none knows call skidim or midwest nautiques..they will know... |
Posted By: TRBenj
Date Posted: February-26-2007 at 7:48pm
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SkiDIM will probably know. If you can wait another 6-8 weeks, I should have mine off by then. ------------- |
Posted By: M3Fan
Date Posted: February-26-2007 at 8:20pm
| There is no check valve in the invertaflo. I've had mine completely out of the boat- no rattles that I know of. |
Posted By: 79nautique
Date Posted: February-26-2007 at 8:51pm
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then it might be one of the baffles coming apart inside of the muffler then. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 87BFN owner
Date Posted: February-26-2007 at 9:30pm
Posted By: M3Fan
Date Posted: February-26-2007 at 9:40pm
| I love the single exhaust when I'm skiing the course on public water at 7AM on a Saturday. I can't imagine that the people on this lake enjoy a thundering V8 noise after a hard week of work at the crack of dawn on a Saturday. The single exhaust is the result of extensive muffler research which really works. As much as I love the "music" of the older boats, I can tell you that where I ski, at the times I ski, I love a quiet boat. No other ski boat manufacturer can match the quietness of the invertaflo or hull hugger muffler. |
Posted By: 79nautique
Date Posted: February-26-2007 at 10:30pm
mufflers and quit exhaust are for pussies, 
he does have a good point but screw'm it's saturday get up and enjoy the day. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: MaddMarxx
Date Posted: February-27-2007 at 1:21am
| I would like to cut one them open just to see what it looks like inside, maybe it can be gutted to pick some HP.. |
Posted By: jameski
Date Posted: February-27-2007 at 7:55am
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Thanks for all the input.
MaddMarxx, I'm almost curious enough to cut mine open - but I've never done much fibergla$$ work, so I probably better not. When I was a kid, I took off the catalytic converter on my car and knocked all the gutts out and put it back on to gain some HP. 
79nautique, you may be correct about the baffles coming apart, because I don't think I have any baffles. I was very pleasantly surprised with the exhaust note the first time I drove this boat. I loved the duals on my '78 and I had always heard about how quiet the invertaflow is - my '94 is not quiet. It sounds about the same as my '78 - quieter at idle, but about the same underway. I can see (and reach) inside the the port end and it seems to be just one big (maybe 10") hollow horizontal tube with one slightly smaller (maybe 6") vertical tube at the outlet on the starboard end. The vertical tube has openings at the bottom, and I can barely reach my fingers inside the openings and I feel another piece inside there that can move up and down. ryanandrews, Good idea to call SkiDIM. I'll try that today. TRBenj, Are you removing yours for good? Going back to duals? I considered that, but it looks like the rudder tiller arm would be in the way on the port side. Wouldn't it be cool to add another ma$$ive 4" thru-hull and run huge straight pipes?!!! M3Fan, I'll admit, there are a few times when I would love to have a silent wakeless boat. One time I rounded a bend in the lake pulling a boarder enjoying the gla$$ and found myself in the middle of about 2 dozen john boats full of angry fishermen.  ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: Munday
Date Posted: February-27-2007 at 9:05am
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This guy at the lake called me over to his house.His Sn wouldn't start and his boys been cranking it and pumping the throtle.You can smell gas big time.I tell him I'll bet its the ign. switch,so he wfo's the throtle and shakes the key switch as he is turming it...k f'n boom
it blew the end right off the invertsflow,inside there is a standing pipe so it has to be half full before it starts pushing water out the exhaust and thats the only thing I remember inside,he took it home and did a nice job putting the ends back on it with gla$$. Good luck Munday |
Posted By: M3Fan
Date Posted: February-27-2007 at 9:09am
Yes, he is actually doing this. he's a sick man  .
The invertaflow is pretty loud inside the boat but it's outside the boat on the lake that you really hear the difference. You'd have to be on the shore to really hear the difference. |
jameski wrote:
Posted By: TRBenj
Date Posted: February-27-2007 at 3:32pm
No comment  ------------- |
Posted By: 87BFN owner
Date Posted: February-27-2007 at 6:22pm
Posted By: jameski
Date Posted: March-04-2007 at 8:24am
I went ahead and cut it apart. Here is what I found:
There is a 4" outlet "stand pipe" in the middle of the vertical cylindrical baffle that was not attached to anything. It had been this way for a long time - evidenced by the amount of wear around the bottom. 
Now if I can find someone to repair it and put it all back together... I've never done much fiberglass work, so I don't know if this would be a good practice job for me. New ones are VERY pricey. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: M3Fan
Date Posted: March-04-2007 at 9:20am
| That's probably why it wasn't doing too good of a job suppressing the exhaust noise. Thanks for posting these pics. Until now, the true contents of one of these things was a mystery to just about everyone on this site I'm sure. |
Posted By: 79nautique
Date Posted: March-04-2007 at 9:29am
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Get a new one or leave it out completely, I wouldn't try repairing it. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: TRBenj
Date Posted: March-04-2007 at 9:58am
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Its just fiberglass. Mine hasnt been cut apart like that, but it has been patched and works just fine. If you want to put an invertaflow back in, Id just do a quality repair on that one. Its not that difficult, and well worth saving the $800+ theyre asking for a new one. ------------- |
Posted By: boat dr
Date Posted: March-04-2007 at 11:38am
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TRBenj, I am with you ,ain't hard to repair the pieces that's there .A couple hours labor and a f/glass repair kit is all that is needed.Bail off in it , you don't have nuttin' to save but money.
79 is good with advice and spending other peoples money, i guess he don't do glass.makes his double chip itch.....................boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: jameski
Date Posted: March-04-2007 at 1:20pm
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It seems that the exact contents were a mystery to all the experts too. I called all over the country and didn't find anyone that seemed really sure of themselves. It's not quite what I expected, and it does seem to produce a pretty significant flow restriction. The entire bottom 2 inches of the muffler stays full of water and the exhaust pressure has to force water up and over the stand pipe inside the vertical cylindrical baffle. I have considered leaving all the baffling out for flow/HP, but I really think I might like the quiet boat for a change. I wonder how much restriction it actually adds? The performance of the boat when I bought it actually exceeded my expectation and I hope if I put the muffler back together the way it should be that I won't regret it due to a loss of performance.
I'm really hesitant about doing the repair myself, but I know there are some fiberglass repairmen that could probably make easy work of it. As TRBenj said, it beats the cost of a new one. The lowest price I've been quoted so far is $560 (but I haven't really shopped around much). ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: eric lavine
Date Posted: March-04-2007 at 2:03pm
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I wonder if you could make one of these out of pvc and fiberglass, that would be in-expensive...... $560.00 thats a little pricey ------------- "the things you own will start to own you" |
Posted By: Guests
Date Posted: March-04-2007 at 5:55pm
| what was the reason to cut it open again........ 600.oo thats a sh*t load of money for an exhaust muffler.... |
Posted By: jameski
Date Posted: March-04-2007 at 6:22pm
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I had to cut it open to repair it. I didn't know exactly what had come loose, but I knew something had. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: 87BFN owner
Date Posted: March-05-2007 at 8:20pm
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must be a cadilac stamp somewhere on that muffler to make it cost 6 big ones. ------------- http://i150.photobucket.com/albums/s95/buckethead1236/Barefooter6-10-09002.jpg" rel="nofollow - MY 87BFN |
Posted By: jameski
Date Posted: March-27-2007 at 11:43am
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After mutilating my invertaflow and finding the problem, I took it to a local auto-body shop known for doing fiberglass work. They kept it for a while, but they did good work and got it all put back together probably better than new for $320. I'm running it now and it IS quieter in the boat and it has a pretty nice rumble out the transom. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: JoeinNY
Date Posted: March-27-2007 at 11:48am
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Well could have been worse then, glad to hear your back on the water. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: tapenick
Date Posted: August-20-2012 at 2:13am
I've been wanting to ask if a PVC Y-pipe might hold up in place of the Invertaflow (along with some flexible exhaust hose). So it wouldn't be too much heat for PVC? |
Posted By: Gary S
Date Posted: August-20-2012 at 2:35am
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I would not chance it,it's the only thing between you and the bottom! Looks like schedule 40 pvc pipe is rated to 140 degrees, cpvc 180 degrees ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Bri892001
Date Posted: August-20-2012 at 11:57am
This problem has a solution already. I believe both Race City Marine and MyCorrectcraftparts sell a special 2 into 1 Y pipe for this. |
Posted By: Foot_Fungus
Date Posted: August-21-2012 at 3:18am
| the y-pipe alone is $175, not to mention another $50-60 for the additional hose. Cheaper route would be to cut the invertaflow open and remove the baffle tube then glass it back together for $40. Granted, so far I've only seen posts on the hull hugger versions, but the invertaflow shouldn't be different repair wise. Most have said the glass has held up with no durability issues thus far. I'll be doing it this winter so if you're in no hurry wait and see how it goes. |
Posted By: jameski
Date Posted: August-21-2012 at 5:25pm
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Foot_Fungus is giving wise advice. I can testify that after the repair that I posted above in February 2007, I am now in my 6th hard season of skiing/barefooting with my repaired invertaflow with NO PROBLEMS! repairing the fiberglass is the way to go. ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: kapla
Date Posted: August-21-2012 at 7:04pm
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Unless you want to go mufflerless...yes the invertaflow if easily repairable with little to no experience in Fiberglass... Actually my first job using this material was fixing the muffler. Mine blew up a couple of times and it´s been 3 years since last repair... ------------- <a href="">1992 ski nautique |
Posted By: tapenick
Date Posted: August-22-2012 at 12:28am
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Update - the kit from mycorrectcraftparts is $471 plus shipping. I guess this would rust out quick? Wasn't sure since it was "aluminized": %20" rel="nofollow - http://www.jegs.com/i/Flowmaster/389/Y300400/10002/-1?parentProductId=744773 Leaning toward just modifying / repairing the Invertaflo as suggested. So to get rid of the muffling just cut the tube off inside the "barrel"? My other issue is that the inlets look restrictive. Almost conical shaped. I'd like to cut those off and do-over. Guess I'd need something slightly smaller in diameter than the hose that connects to the manifolds. Thoughts/ideas? |
Posted By: Foot_Fungus
Date Posted: August-23-2012 at 2:14pm
| the way the invertaflow works is its a tube over tube setup. so it forces the exhaust gas through a few inches of water to get to the bottom opening of the outter tube, then up to get to the opening of the inner tube. My plan is to remove both tubes and or remove a few inches of the outter tube so the exhaust doesn't have to pass through as much water, but i still keep some of the noise baffling characteristics... I'm gonna tear mine apart in November. |
Posted By: tapenick
Date Posted: March-24-2013 at 2:51am
Update? |
Posted By: ononewheel
Date Posted: November-25-2013 at 6:40am
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Just here to post some photos of inside a muffler. Boat is a 94 Excel/barefoot. These pics are of the "cap" which is glassed on the top. Pics of repair to come after I actually repair it. I was moored and on restart the engine backfired LOUD. I inspected the engine area and that is what I saw. Shattered the "cap", found it in about 20 pieces. Hopefully, this helps for those who want to know how the muffler works.   ------------- If we let the professionals do everything it takes all the fun out of youtube |
Posted By: dochockey
Date Posted: November-28-2013 at 12:30pm
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Yours is the second muffler I' ve herd of where a back fire caused that cap to blow off . The first was mine, My exhaust flap had fallen off and a muskrat made nest condo in the tube which caused the backfire when it happened the engine cover was up and that cap blew up into a million peices and hit one of the passengers in the shoulder  I baught a new one at the time. I wish i kept the old one .------------- 1989 Teal Ski Nautique 1967 Mustang Harris Float Sunfish |
Posted By: jameski
Date Posted: January-30-2015 at 7:06pm
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Well... My repair (originally posted on this thread 8 years ago) has lasted just fine... up until now. I had a weak battery and a small jump-starter and after a few cranks, KABOOM!!! Backfire blew the side off and blew the top "hat" to bits. It was such a big explosion, it actually broke both of the plastic doghouse hinges. This time will be much more difficult to try to repair because the top "hat" will have to be reconstructed. I think I'm probably better off looking for a used replacement. Anyone got a used invertaflow they want to make me a deal on? -James ------------- current boat http://www.correctcraftfan.com/diaries/details.asp?ID=1977 - 94 Sport Nautique previous boat http://www.correctcraftfan.com/diaries/details.asp?ID=601 - 78 Martinique |
Posted By: JPASS
Date Posted: January-30-2015 at 8:34pm
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I'm in the process of repairing my invertaflow. In my http://www.correctcraftfan.com/forum/forum_posts.asp?TID=35272&PN=1&title=invertaflow-muffler-question" rel="nofollow - thread Air206 mentioned he had one for sale. I'd hit him up. ------------- '92 Correctcraft Ski Nautique |
Posted By: Air206
Date Posted: January-30-2015 at 9:30pm
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Jameski- I have one. Email me at 78skitique at gmail.com ........... Steve ------------- https://tinyurl.com/y6t5e3bu" rel="nofollow - 04 Air206 http://tinyurl.com/9urzgls" rel="nofollow - 91 Barefoot 78 SkiTiq |
Posted By: tapenick
Date Posted: January-30-2015 at 9:35pm
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I ended up buying a Y pipe and some hose from skidim for about $150 (total) and it was great. (eliminated the Invertaflow) Tom |
Posted By: JPASS
Date Posted: January-30-2015 at 9:56pm
You must have got some killer deal. The exhaust hose alone would cost that with shipping. ------------- '92 Correctcraft Ski Nautique |
Posted By: tapenick
Date Posted: January-30-2015 at 10:21pm
Could be off... been a year or two. Thinking harder, seems like the Y was close to $100 I think it took 7' of 3" flex. Ugh, yeah that would be ~ $140. Maybe it was $250. :) I do recall that shipping was nowhere near as bad as I thought it would be. Anyway, call Richard at skidim and he can walk ya through it. Or reply back and I can answer any questions. |
Posted By: Erikgundy98
Date Posted: February-27-2021 at 1:47am
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To all you who did the repairs on your inverta-flo, did you have to recreate the top bubble or cap above the baffle? How did you do that? Thanks! Or does anyone still have an extra laying around they want to sell? :) |
Posted By: 8122pbrainard
Date Posted: February-27-2021 at 7:37am
Erik, It sounds like you don't have the cap anymore so a repair isn't feasible? So, you will need to make a male mold to lay up the glass shape of the cap'bubble. The easy way to make the male "plug" is on a wood lathe but it could also be made it with tools like a band saw and belt sander. The plug is coated with a good layer of wax or even better, realease agents are available in aerosol cans. This coating is so you can remove the glass from the plug after the glass has cured. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Gary S
Date Posted: February-27-2021 at 8:00am
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Wouldn’t cost anything to contact Centek and ask if they would sell that part..... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: nobrainsd
Date Posted: February-27-2021 at 12:42pm
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Thankfully when my Invertaflow failed it was just the baffle that came loose. But I understand your situation where you need to make a "bubble" top. Considering how much a new muffler costs and how much they cost to ship it would probably be worthwhile to make a "bubble" cap yourself. I happen to have epoxy, woven fiberglass and glass matt already, so I would definitely fabricate a part. I used a contour gauge on my existing "bubble" cap. From there it would be easy to make a mold. I would go simple and either use some old surfboard foam (I have lots of) or modeling clay. My contour gauge outline is from the outside. So if you wanted to make a plug it would require drawing the outline reduced by the thickness of the part you are shooting for. If you wanted to make a mold (concave) the outline would work fine. If you used modeling clay it would be easy to cut the outline into a sheet of plastic and use it to shape the clay after roughly approximating the shaped clay. In reality the "bubble" is not a critically designed or manufactured piece. So it isn't crucial to have a precise piece made. I wouldn't coat and cover the mold with release. I would just cover it in thin plastic sheet. A fold here or there or an overlapped seam isn't going to be an issue in a molded part like this. You just want to deflect the water flow around the baffle rather than have it splash in mostly one direction. A layer of woven glass, a layer of matt and another layer of glass and some spray paint will give you a cap that will epoxy right back on. I would definitely lap the seam from the "bubble" to the muffler body with some woven glass :) Non reinforced epoxy is not that strong. Have fun with epoxy out there. It's easy to do. The image below is not to scale. You will either need to scale it to fit or PM me and I can send you a full size file.
|
Posted By: Jonny Quest
Date Posted: February-27-2021 at 5:45pm
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I'm trying to NOT make a comment on the above image...
Kinda reminds me of the logo from the Average White Band from the 1970's  ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: nobrainsd
Date Posted: February-27-2021 at 7:26pm
| But... :) That is why I refer to the "bubble" in quotes. Doesn't look like a bubble. |
Posted By: nobrainsd
Date Posted: February-27-2021 at 7:42pm
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There is an invertaflow muffler for sale on ebay right now. $29 and $125 postage. Looks like it needs repair on the exhaust port, but the bubble and body appear to be intact. |
Posted By: KENO
Date Posted: February-27-2021 at 7:49pm
I'll bet it belongs to somebody here on the website whose screen name starts with an R and ends in iley
 |
Posted By: Riley
Date Posted: February-28-2021 at 8:20am
Yeah, that is ours and it is for sale for $29 or make an offer, so it can be had for less. Shipping on my end shows $33.88. I don't know how ebay estimates their shipping estimates, but they are often inaccurate. It has been repaired, which looks like it is coming undone, but it did not appear to leak when we ran the boat we removed it from, which was a 1989 Martinique that went to the dump.
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Posted By: KENO
Date Posted: February-28-2021 at 8:52am
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If you put a San Diego zip code (where nobrainsd is located) in the EBAY shipping estimator it comes out to 125 and some change. (USPS Priority Mail) Same 33 and some change to me in NH as you mentioned Bruce. Like you, I have no idea how their estimator works
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Posted By: Lou-Pa
Date Posted: February-28-2021 at 9:21am
| AWB - my favorite band from the college days. Thanks for the memories! |
Posted By: nobrainsd
Date Posted: February-28-2021 at 9:39am
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Strange. I did not enter my zip code in the shipping calculator to get the postage amount. The listing came up with Expedited Postage $125. Now I see the listing shows Calculate. EBay at it's best! But I will definitely stay aware that when considering items on E Bay that the postage isn't necessarily what is shown! Still looks like a pretty good deal :)
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Posted By: Riley
Date Posted: February-28-2021 at 11:23am
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I use USPS as much as I can, but west of the Mississippi Fed Ex is much cheaper.
We occassionaly part a boat out for parts we need and sell the stuff we don't need on ebay. After awhile, I just get tired of moving it around or stepping over it. The best deals we have are the new parts we buy and then decide not to use. We take a beaten on those, especially when I get tired of looking at them.
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Posted By: 8122pbrainard
Date Posted: February-28-2021 at 2:14pm
Bruce, The PO must have done the "repair" since I know you sure wouldn't have made that mess. I wonder if the PO missed his PB in his PB&J sandwich! I have no idea what he used. That tan stuff doesn't look like anything I'm familiar with. EDIT: I have a feeling the repair was done with West System using their 410 fairing filler. Not the best choice since the 410 is primarily wood flour hence the color. Easy to sand but low strength.
------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |