Exhaust Bellow

Brody133

Seaman Apprentice
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Aug 23, 2022
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32
So I ordered an exhaust bellow off of Amazon and in the description it said it was for my boat, but look at this thing. I thought they were supposed to be sealed? Will it work?7411EC56-7F37-438F-9417-D476E8926653.jpeg
 

Scott06

Admiral
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Apr 20, 2014
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Was it one of the cheap kist they have ? Looks like junk to me .
 

Renken2000Classic

Petty Officer 1st Class
Joined
May 10, 2022
Messages
233
What's wrong with it?

That part goes down.

I bought my boat (OMC Cobra) with a torn up exhaust bellows. PO asked his mechanic about replacing it, and the mechanic said Why? I replaced it the next season. Anecdotal. Idk if it matters more on Volvo Penta or not but I doubt it. U-joint bellows is another matter...
 

Brody133

Seaman Apprentice
Joined
Aug 23, 2022
Messages
32
What's wrong with it?

That part goes down.

I bought my boat (OMC Cobra) with a torn up exhaust bellows. PO asked his mechanic about replacing it, and the mechanic said Why? I replaced it the next season. Anecdotal. Idk if it matters more on Volvo Penta or not but I doubt it. U-joint bellows is another matter...
Just seems like it should’ve been one piece without holes to keep water from running back up into the exhaust manifold I guess or to allow exhaust gases to escape properly. I’m no boat mechanic though.
 

Scott06

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Apr 20, 2014
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6,427
They’re supposed to be one solid piece right? No holes?
Yes does it hurt anything if exhaust bellows are ripped, no they are open to water anyways. Ight be a tad louder, but why put on a torn one …return it
 

Lou C

Supreme Mariner
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Nov 10, 2002
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That’s the OMC Cobra version. It’s supposed to be like that to reduce back pressure. The VP version has holes in it too but smaller ones. You can use that with no problem.
 

Scott06

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That’s the OMC Cobra version. It’s supposed to be like that to reduce back pressure. The VP version has holes in it too but smaller ones. You can use that with no problem.
Good to know thank you
 

tpenfield

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Jul 18, 2011
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That's a new one (to me) . . . I have not seen a bellows like that, but exhaust bellows don't have to be water tight, since they are under water anyway and fill up when the boat is at rest.

@Brody133 . . . do you have the prior/original bellows for comparison?
 

Lou C

Supreme Mariner
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Nov 10, 2002
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The reason why there is confusion here:
OMC had the Cobra, and VP had the AQ drives
The Cobra was designed to use the same cut out in the transom as the Merc drives unlike the OMC Stringer and the Volvo AQ drives.
When they ran into financial trouble, VP bought into their sterndrive divison. VP wanted their standard transom design. So in '93/94 a new product was brought out, the new Cobra/Volvo SX Cobra. What the engineers did was take the OMC transom mount, modify it slightly and re-engineered the drive to use cone clutch shifting. Both the 'new' OMC Cobra and the Volvo SX Cobra were identical products just painted different colors. The u joint bellows was the same part because of the similarity of the transom mount designs. However it appears that the exhaust bellows on the 94 and up for both changed to one without the slits but small holes on the bottom side. And later still Volvo they totally changed the u joint bellows. But the OMC Cobra parts for both will fit a Volvo SX. Yes its confusing. But the exhaust bellow mounts the same way on both with a hose clamp on the gimble housing end and a circlip on the pivot housing end.
 
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Brody133

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Aug 23, 2022
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32
That's a new one (to me) . . . I have not seen a bellows like that, but exhaust bellows don't have to be water tight, since they are under water anyway and fill up when the boat is at rest.

@Brody133 . . . do you have the prior/original bellows for comparison?
Prior one from what I can remember was solid. I’m assuming it would be ok though, just strange. Let me ask you as well as anybody else, and I’ll dive further into the situation if enough people reply back; is it possible for your engine to overheat due to not having an exhaust bellow? (As in too much water in the exhaust components and is trapping the exhaust gases in the manifold.) I noticed my exhaust bellow was completely torn off when I got back home from the lake and earlier that day my boat had overheated, but luckily I was able to limp it back to the dock.
 

Bondo

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Prior one from what I can remember was solid. I’m assuming it would be ok though, just strange. Let me ask you as well as anybody else, and I’ll dive further into the situation if enough people reply back; is it possible for your engine to overheat due to not having an exhaust bellow? (As in too much water in the exhaust components and is trapping the exhaust gases in the manifold.) I noticed my exhaust bellow was completely torn off when I got back home from the lake and earlier that day my boat had overheated, but luckily I was able to limp it back to the dock.
Ayuh,.... Welcome Aboard,..... Volvo, 'n OMC have used holey exhaust bellows for a long, long time,....
It don't matter, as the exhaust is always fulla water,.... usually to the top of the y-pipe, til the motor is started,....
'n No, it won't cause an overheat situation,.....
Look to the raw water pump impeller for that, 1st,.....
 

Horigan

Senior Chief Petty Officer
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Jun 12, 2016
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673
Prior one from what I can remember was solid. I’m assuming it would be ok though, just strange. Let me ask you as well as anybody else, and I’ll dive further into the situation if enough people reply back; is it possible for your engine to overheat due to not having an exhaust bellow? (As in too much water in the exhaust components and is trapping the exhaust gases in the manifold.) I noticed my exhaust bellow was completely torn off when I got back home from the lake and earlier that day my boat had overheated, but luckily I was able to limp it back to the dock.
A torn exhaust bellows won’t affect engine cooling.
 

Brody133

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Aug 23, 2022
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32
Ok, so since it’s overheating, I’m assuming I’ll start at the water pump first then if it’s overheating and just go from there.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Ok, so since it’s overheating, I’m assuming I’ll start at the water pump first then if it’s overheating and just go from there.
That is always where you start
 
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