Exhaust bellow types

[Merccoper]

As I'm doing all the work after my submerged engine fiasco I decided to replace the bellows. After opening the new bellows kit package I realized I got a different exhaust bellow than what was originally on. I'm assuming this is alternate version that doesn't exhaust through the outdrive? Is that correct, or did I get the wrong one?

If I'm correct and this is an alternate version, how much louder does this make the engine sound?
Any other pros/cons?
(It's for a Alpha one Gen 2 outdrive)

 

[achris]

Is this an OEM kit, or aftermarket?

 

[harringtondav]

I think that is called an exhaust tube. Kinda like a poor man's thru hull exhaust. Previous posts indicate louder engine noise. It may be more efficient than thru the prop exhaust, but you may also loose some backwash protection. Then it's up to the engine exhaust tube flappers to keep a big back wave out of your exhaust manifold. That generally doesn't turn out well.

 

[achris]

Merc never made an exhaust tube for Gen II... The original tube was only ever factory supplied on Alphas with 454s... And that only lasted a year or 2... It was so the exhaust back pressure was relieved at low speed...

I hear a lot of people putting the tube on because it's easier... Which I find odd, because I've never had a problem with the bellows. But then again, I only use OEM bellows, and I have the right installation tool and follow the instructions on the manual.

Chris.....

 

[whiskeyRichard]

I recently installed this exhaust tube after doing lots of reading about it. I was actually hoping to get a little more rumble from the motor, but it was just a very small increase in sound. Certainly not enough to bother anybody.

Installation was a breeze.

 

[dlogvine]

I installed tube bellows instead of a regular one. Did not see any difference in the sound level. Was a lot easier to install though

 

[metsfan3197843]

Did not see any difference in the sound level.

A real smart *** would throw a barb in here....but I'm not a smart *** so I'll keep quiet

 

[ImperialV184]

In my manual it discusses both exhaust tubes and bellows, I don't have it in front of me but I remember that there were performance issues with some outdrives when going from the bellows to the tube, I know my Alpha one recommended the Bellows. I will see if I can dig up the verbiage.

 

[pyrotek]

I had exhaust bellows in my previous boat, single engine bravo. I have twin bravo 3 in my new boat and previous owner installed tubes and it annoys the hell out of me. A lot of people seem to say they like it, but to me it has an obnoxious frequency going 5-7 mph in the channel. Its the first project I'm doing this winter to replace it. Going fast, you can't hear the different between tube and bellow.