Exhaust Tube Bellow is LOUD

[enginesilo]

I changed my bellows last year and had a hell of a time with the exhaust bellow, so I decided to use the Exhaust bellow tube that only connects to the transom side. In the forums say the bellow tube is only slightly louder, but mine is MUCH louder than the bellow that connects to both sides of the housing.

Could I have installed it too far back? If my boat is idling, tall the exhaust gasses bubble up and come out of the top of the bell housing, not the propeller. Could I exhaust bellow be shifted too far back? On land, I tried to trim the outdrive all the way down and it seems like the exhaust bellow tube is meeting the hole on the other side, but its still loud and no exhaust seems to pass out the propeller.

Anyone have any ideas how to quiet this exhaust tube bellow up a bit without installing the normal style exhaust bellow?

 

[achris]

Exhaust tubes will be louder, and the only way to make it quieter is to go back to a bellows. The original idea of the tube was for BBC engines, to allow more exhaust out of the tube, because the back pressure, given the gas volume was impinging on performance. It was the 'through hull you were having without having through hull'.... So yes, going to be LOUD on any engine.... Just sounds terrible on the 4 bangers.

In answer to the question, no, you can't install them 'too far forward' (I think you have back and forward transposed. Forward is towards the front of the boat. Back is away from the boat)...

I have installed many exhaust bellows, and if you try it without the special tool, yeah difficult, damn nigh impossible! With the special tool, piece of cake! I built my own tool. Instruction in the 'special tools' part of the stickies.... Cost me about $3 in materials and 30 minutes of spare time.

Chris.........

 

[Scott Danforth]

MUCH louder than the bellow that connects to both sides of the housing.]

yes they are

Anyone have any ideas how to quiet this exhaust tube bellow up a bit without installing the normal style exhaust bellow?

cant be done, just install the standard bellows

 

[nola mike]

So yes, going to be LOUD on any engine.... Just sounds terrible on the 4 bangers.

I

Chris.........

Just installed one, and it's a bit louder, but not by much. AND it sounds great. Of course, I have a BB 4 banger

 

[Alumarine]

I tried the exhaust tube on my 3.0 and while I liked the sound I found it a bit loud especially for talking to people sitting in the back,
I recently went back to the standard bellows.

 

[thumpar]

It is normal to have the exhaust come up around the transom area at idle. There are idle relief ports for the exhaust and water to escape instead of trying to push it all out the prop. If you have ever run on muffs you should have noticed the water coming out of them. That will not change with a bellows vs. tube.

 

[fishrdan]

Got back to the exhaust bellows if you want quiet. I ripped my exhaust bellows, and knew from the noise, I didn't want the exhaust tube...

Check out this link for an exhaust bellows tool I cobbled up, $3 in misc parts from the hardware store.

FWIW, I replaced my exhaust bellows without removing the drive, fishing trip the next day... It was a royal pain, but not impossible.

- Attach transom side of bellows and let adhesive set for a couple hours.
- Attach several long zip ties to aft portion of bellows, so you create 2 handles to pull the bellows aft
- Coat drive and bellow with adhesive and let dry (30 minutes).
- Tie rope/strap to zip ties, so the bellows can be pulled by someone else standing behind the drive
- Wipe down adhesive with paint thinner (sloooow drying solvent)
- Have someone else pull bellows (my kid) so they slip onto the drive.
- Tighten bellows clamp.

If you're a 1- man show, need to pull the drive and use the a bellows tool.

 

[enginesilo]

Thanks, everyone. So most of you say it is loud, some say it's not that much louder, mine screams loud in comparison to the old exhaust bellow. When I was doing my bellow job I was at the end of my patience and I had the bellow tool and decided to just use the tube. If I remember right I needed to remove a vertical pin that goes down through the exhaust tube in the bell housing and I didn't have the patience to do it anymore. Maybe I'll put the exhaust bellow on one winter when I pull the drive for maintenance.

 

[achris]

That vertical pin is the upper shift shaft. ... And it takes about 2 minutes to get out.