Alpha I Gen I Exhaust Bellow Question

BoatingCop · Dec 29, 2010

I've been reading some on here and other sites about a fixed exhaust tube that goes in place of the factory bellow and only connects to the exaust side and not the actual outdrive. When trimmed down it fits over the flange but when trimmed up it comes out. Now if that's ok to do, what would be wrong with totally taking the bellow out? I ask this because I'll probably be replacing mine but if the only consequence is more exhaust noise I wasn't going to bother with it. Thanks

ziggy · Dec 29, 2010

Re: Alpha I Gen I Exhaust Bellow Question

couple of draw backs with the exhaust tube.

if ya beach. and waves slam against the back of your boat with the drive up and no exhaust bellows. it's more of a direct shot into your exhaust system for forcing water up into the exhaust system. granted the flappers will still inhibit water flow. but?

same with backing.

from what i hear. there is less muffeling going on w/o the exhaust bellows.

ya may get more exhaust smoke on your transom w/o the exhaust bellows..

good would be ease of install i suppose..

TilliamWe · Dec 29, 2010

Re: Alpha I Gen I Exhaust Bellow Question

Yes, the drive does come away from the exhaust tube that you speak of, but only at cruising/planing speeds. So there is no chance of reversion at all there. Ziggy mentions the reason to have the bellows. I will say that my Bravo 3 had the tube, and I did tilt the drive all the way up and sit "beached" stern in a lot. I never had a problem, but there also weren't waves coming out from the shore hitting the transom of my boat either.

zbnutcase · Dec 29, 2010

Re: Alpha I Gen I Exhaust Bellow Question

Stick with the bellows!

FreeBeeTony · Dec 29, 2010

Re: Alpha I Gen I Exhaust Bellow Question

I would go w/ the tube..........alot easier to install.

I have been using 1 for a few years w/o any problems.

BoatingCop · Dec 29, 2010

Re: Alpha I Gen I Exhaust Bellow Question

Yeah, I'm leaning towards the tube. I was looking for the hose clamp closest to the boat but couldn't see it. I can see the one on the outdrive but not the other end. Is it glued on that end and needs to be cut off?? Also, just out of curiosity, where are the flappers located in the Y pipe? Thanks

TilliamWe · Dec 29, 2010

Re: Alpha I Gen I Exhaust Bellow Question

BoatingCop said:
...Also, just out of curiosity, where are the flappers located in the Y pipe? Thanks

They should be at the top of the y-pipe.

dubs283 · Dec 31, 2010

Re: Alpha I Gen I Exhaust Bellow Question

what would be wrong with totally taking the bellow out?

the exhaust tube you speak of is not designed for an alpha one drive

it is designed for a bravo 3 drive

the only reason the tube is available is because the twin prop design on the bravo 3 creates such a great vacuum that it collapses the exhaust bellows orginally in place on a bravo 3 transom assy that the engine would loose power and "sputter"

if you are comfortable pulling your drive, inspecting all neccessary components, checking engine alignment, etc...and replacing the exhaust bellows - go for it!!

otherwise, take your boat to a reputable shop and have them perform the proper repair - keep in mind you will be suppoting your local economy!!

also...noting you don't know where the exhaust flappers are/what purpose they serve, you may want to have a shop check things out for you

Fun Times · Dec 31, 2010

Re: Alpha I Gen I Exhaust Bellow Question

[dubs283]it is designed for a bravo 3 drive.

Plus now the Integrated and Hi Performance Transoms using B1-3 & BlackHawks drives get to use the tube as well, Seen here,
http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=891749001

I agree with Dubs and everyone else that said stay with the bellows, Due to the fact that your boats application does not call for the use of the "TUBE" to be used on your boat safely according to mercruiser marines part diagram or they would have specified it in their "Parts Description" like they did for all of their certain types of bravos & alphas setups they have out on the market using certain style engines.

Here's your boats application, see #19
http://www.mercruiserparts.com/Show...0065.png&inbr=2203&bnbr=60&bdesc=BELL+HOUSING

Also boat performance has been known to change using either the bellows, the tube, or completely removing it, Sometimes it's better, sometimes it worse.

BoatingCop · Dec 31, 2010

Re: Alpha I Gen I Exhaust Bellow Question

dubs283 said:
also...noting you don't know where the exhaust flappers are/what purpose they serve, you may want to have a shop check things out for you

Where did I say I did not know what purpose the flappers served?? I'm extremley aware of what they do, just didn't know where in the y pipe they were located. I have almost always done my own work uunless it's something major or something I don't have time, space, or tools for. Thanks for the replies.

That would make sence that the tube is for the Bravo 3

FreeBeeTony · Dec 31, 2010

Re: Alpha I Gen I Exhaust Bellow Question

Here is another thread to take a look at.......

http://forums.iboats.com/showthread.php?183457-Mercruiser-exhaust-tube-vs-bellows

vandentr · Apr 20, 2011

Re: Alpha I Gen I Exhaust Bellow Question

Regarding the exhaust tube and its rationale with respect to the Alpha One drives, I propose that we defer to the manual:

-TVB

StevenT · Apr 20, 2011

Re: Alpha I Gen I Exhaust Bellow Question

Eric I have the same Mercruiser 350 1985 Alpha One. Years back I replaced with exhaust bellows. Last summer I replaced with the exhaust tube. The tube is much easier to install. I can hear a slight difference. More of a deeper exhaust tone. Personally I'll never go back to bellows.

Alpha I Gen I Exhaust Bellow Question

Chief Petty Officer

Admiral

Banned

Commander

Captain

Chief Petty Officer

Banned

Vice Admiral

Moderator

Chief Petty Officer

Captain

Petty Officer 3rd Class

Petty Officer 1st Class