Exhaust Bellow leak??

Hey guys I bought a merc 120 it runs strong with muffs on but the exhast water isint coming out of the prop area its just droping down between the drive unit and the gimbal. my first thought is the exhaust bellow.

any ideas??

and if it is what does fixing it entail parts, tools, time, and if i decide to not fix it myself whats the est cost.

thanks
Jon

Re: Exhaust Bellow leak??

sorry special tools

Re: Exhaust Bellow leak??

The Exhaust Bellows by themselves are under $40.

If you are going in that far you might as well replaces everything that moves. $125.
All the special tools for all the common chores back there; Exhaust Bellows, Drive Bellows, Gimbal Bearing, Engine Coupler. $90

Labor to do the job; An easy weekend job for you; $500-$1000 for a shop.

Re: Exhaust Bellow leak??

UncleWillie said:

The Exhaust Bellows by themselves are under $40.

If you are going in that far you might as well replaces everything that moves. $125.
All the special tools for all the common chores back there; Exhaust Bellows, Drive Bellows, Gimbal Bearing, Engine Coupler. $90

Labor to do the job; An easy weekend job for you; $500-$1000 for a shop.

Click to expand...

now reading a few other posts i see that not all the drives have an exhust bellows. and whats the allignment tool allign? ive also seen some thing about an exhaust tube do they work for 120's

If

Re: Exhaust Bellow leak??

Exhaust bellows have holes in them to drain water when not in use. Are you sure this isn't where it's coming from?

Alignment tool aligns motor/engine coupler/gimbal bearing.

Re: Exhaust Bellow leak??

skydiveD30571 said:

Exhaust bellows have holes in them to drain water when not in use. Are you sure this isn't where it's coming from?

Alignment tool aligns motor/engine coupler/gimbal bearing.

Click to expand...

No Im not sure
but there is zero coming from the propeller area
but I think in need to take a closer look tomorrow and see if its even connected to the drive or how corroded. It was starting to get dark and I didnt want to dive into it tonight. but I thought Id ask.

Re: Exhaust Bellow leak??

I don't know whether you have bad bellows or not, and it would be a very good idea to replace or at least very closely inspect the bellows if the boat is new to you, however, what you are seeing might be completely normal. At the bottom of the gimbal housing where the drive attaches to the boat, there are two idle relief ports (basically just holes) where the vast majority of the exhaust and water leave the exhaust at idle. When on muffs, I get nothing more than mist out the prop hub, mostly exhaust gasses out one port and most of the water out the other. They are all connected-it's just a matter of path of least resistance.

If the exhaust bellows is leaking-no big deal, you could even operate the boat just fine without one (though they are there for a reason). It would be a bit noisy though If you have leaks in the shift cable bellows or u-joint bellows, you could fill the boat with water (bad) or at least cause expensive damage to parts that are supposed to stay dry (esp. in the u-joint bellows). It would be a great idea to pick up an alignment tool on e-bay or have a machinist friend make one for you (there are the specs in the "Adults only" section at the top of the forum, along with tons of other helpful info on alignment and other maintenance items), pull the drive, check alignment, and closely inspect the u-joint bellows. You will also need a gasket set when you put it back together.

Enjoy your new boat!

Re: Exhaust Bellow leak??

I think UNSUREBOATGUY hit it. The idle relief ports are probably where you are seeing exhaust. With the engine not running look close and you will see them.

Re: Exhaust Bellow leak??

I have one noisy exhaust bellows low idle nothing from the prop, get under load exhaust come out of the prop, I believe muffs and low idle pressure too low to push out of prop hub. really has no effect on operation of boat other than idle there can be a louder exhaust sound.

Re: Exhaust Bellow leak??

UncleWillie said:

The Exhaust Bellows by themselves are under $40.

If you are going in that far you might as well replaces everything that moves. $125.
All the special tools for all the common chores back there; Exhaust Bellows, Drive Bellows, Gimbal Bearing, Engine Coupler. $90

Labor to do the job; An easy weekend job for you; $500-$1000 for a shop.

Click to expand...

So I took a look at it and maybe I should have just looked first the bellow is completly rotten. I

I am def gonna replace all the parts above now

is a exaust tube or bellow better What are the pros and cons.

should I order online or should I get the parts local.

Re: Exhaust Bellow leak??

Atlas83 said:

is a exaust tube or bellow better What are the pros and cons.

Click to expand...

Pro is you only need to attach it to the transom side and nothing to attach to the bellhousing.
Con is when running on the muffs it will be slightly louder; negligible when running in the water.

Atlas83 said:

should I order online or should I get the parts local.

Click to expand...

Kind of depends on if you want to use OEM parts or aftermarket such as Sierra. You will get different opinions on that and some guys use a mixture of both but if you go aftermarket, check here at IBOATS for very competitive pricing.

Mark

Re: Exhaust Bellow leak??

The exhaust bellows requires a tool to install and the tube does not. So I have a tube and suggest it.
When the drive is down the tube touches the port where the bellows would attach. This routes most of the exhaust through there, the rest bubbles out the sides. Underway when trimmed up it makes no difference in the sound from my boat.

Re: Exhaust Bellow leak??

If you replace the u-joint bellows (which is advisable since the exhaust bellows is rotten) I would recommend using an OEM part. I know Don recommends OEM u-joint bellows because it is such an important part.

Re: Exhaust Bellow leak??

Atlas83 said:

So I took a look at it and maybe I should have just looked first the bellow is completly rotten. I

I am def gonna replace all the parts above now

is a exaust tube or bellow better What are the pros and cons.

should I order online or should I get the parts local.

Click to expand...

An exhaust tube will allow more dirty exhaust film to coat your transom, whereas exhaust bellows will direct most of it away from the boat. I have a tube fitted to mine but I'm thinking about fitting a bellows next time I have it apart for that very reason.

Re: Exhaust Bellow leak??

Cresco750 said:

An exhaust tube will allow more dirty exhaust film to coat your transom, whereas exhaust bellows will direct most of it away from the boat. I have a tube fitted to mine but I'm thinking about fitting a bellows next time I have it apart for that very reason.

Click to expand...

The Merc doesn't even need a bellows to work properly. It just basically keeps everything cleaner and quiter. Also keeps the exhaust fumes to a minimum while on plane.

I saw the same thing on my boat. Replaced bellows w/ the tube a couple of years ago, for what ever reason. Transom has more exhaust residue on it than before. At idle / non planing speeds, in the water, the noise is the same as the bellows, but on plane and trimmed out a bit, the big ol' 454 is deffinately louder w/ the tube. Was fun for the first 15 minutes, but noise got a little annoying and some conversation / listening to the radio had to be elevated to overcome the exhaust note and the admiral was not real pleased, so back to the bellows it was.

Performance wise, it made zero change, that I could see, and the bellows is actually cheaper than that simple little tube. Go figure....

Re: Exhaust Bellow leak??

Thanks everyone. I ordered the tube
Reasons
1 and biggest reason Easy Install
2 doesn't really matter about the sound it's either myself or or a couple people fishing so we don't get up on plan that long so noises isn't a factor.
3. Same as number 1

But I sure hope all the other parts are easy to instal

Thanks again

Re: Exhaust Bellow leak??

Thanks again for telling me to pull the drive. I now have to replac a front seal on the drive the gimbal ujoint and maybe a yoke

If interested why check the chocolate milky grease thread