Invertaflow Muffler on ’94 Sport Nautique

hmmm.if none knows call skidim or midwest nautiques..they will know...

There is no check valve in the invertaflo. I've had mine completely out of the boat- no rattles that I know of.

not a fan of the single exhaust outlet at all. CC's were ment to have dual exhaust. Anyone else think this way?

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.

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.

jameski wrote: 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?!!!

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.

when I had the 2001 sport with the python in it, at 1200rpms while the boat was moving the ba$$ coming from the exhaust was so strong you could hear yourself think it was great. Everyone I met wanted to know what was under the cover. Suprised a baja or two with trip 502's. They just couldn't figure out why, silly guys and the cig boats. Top end they had me for sure by a mile but, the race ain't that long.

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.

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.

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).

what was the reason to cut it open again........ 600.oo thats a sh*t load of money for an exhaust muffler....

must be a cadilac stamp somewhere on that muffler to make it cost 6 big ones.

Well could have been worse then, glad to hear your back on the water.

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

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.