[jetinspector]

I have a hole in my exhaust bellows and will be replacing it this winter, has anyone been able to do this without pulling the entire outdrive off? I would really rather not pull it off but I will if need be. What should I expect in pulling the outdrive off if that is what I have to do? Any special tools or gasket/o-ring kits that would be required? I am a mechanic so I can and will do all my own work but am looking for advice from people who have already been there done that! Thanks!!

[ColoradoDiablo]

Change them both jet.
If one has a hole , the other one ain't far behind from leaking. And if you get a hole in the drive boot.........it's gonna get spendy.
If I remember right , you got a 1990 right?

HERE is what you need to repair it properly.

HERE is a good explanation of the process.

Not that bad of job , just a little time consuming. And take your time sticking the drive back in.
A service manual will do wonders for helping out too.
Available to contributing members if your interested.

[Hudson River Steve]

I've replaced a number of exhaust bellows on various drives (Alpha's and Bravo's) over the years. I would not bother with a bellows again, instead I would replace the bellows with an exhaust tube. It is only attached to the transom assy and gloves over the fitting on the gimble ring. It was developed for higher HP motors but it makes replacement much easier. The boat is slightly louder at idle but I don't notice any difference at speed. You can check out this thread for more discussion Mercruiser exhaust: tube vs bellows*/ 183457
It has also been my experience that the exhaust bellows gives out much sooner than the drive shaft bellows due to the hot exhaust gasses and hot water running through them. That being said, as Larry points out...if the drive shaft bellows fails...you have some real problems, so if there is any doubt...change it too.

[jetinspector]

How does the exhaust tube keep water from coming back into the boat with the lower unit raised? I have a water leak that I have found leaks worst when the lower unit is raised and the hole in the exhaust bellows is stretched, should this hole be leaking into the boat or do I have a hole somewhere else also? Unfortunately I have not been able to get back underneath there to get a good look.

The entire lower unit was replaced with new last summer at the end of the season so the drive shaft bellows is in decent shape. I did however find a small hole in the linkage bellows so I will probably just replace all three before next year.

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[ColoradoDiablo]

If it is leaking worse with drive up , I'd be looking at the drive bellows.
You'll lose u joints , gimble bearing , etc. if it's leaking.

If you wanted to , you don't even have to have a exhaust bellows. It is basically a diversion to get the exhaust away from the boat as far as possible. With some vented props , it helps to "slip the prop" for a better holeshot , but I ain't convinced it helps.

Exhaust flappers and the mere height of the top of the exhaust manifolds above the waterline keeps water from entering the engine jet.

[jetinspector]

Exhaust flappers and the mere height of the top of the exhaust manifolds above the waterline keeps water from entering the engine jet.

--duh! lol

The drive bellows look pretty good, and if the drive bellows were leaking would I be getting water into the lower unit drive oil? I changed the drive oil after I had put about 4 - 5 hours on it after we bought it since I was told the new lower had about 5 hours on it, and at that time the oil was clean and there was no evidence of water in the oil. I might need to just take the lower off and do some exploratory surgery.

If I can get the time, I need to remove several panels around the engine, take it to the lake, leave it on the trailer and see where the water comes in exactly.

[jetinspector]

To answer your first question, yes it is a 1990. I have been really happy and impressed with the boat ever since I got it. Just working out the little issues and getting it to the condition it needs to be in.

[ColoradoDiablo]

If the seal is good at the moment...........no , you won't get water in the drive.
The exhaust tube won't let water in the boat period , unless the Y pipe gasket fails at the transom.

[jetinspector]

Hmmm Thanks that gives me more to look into! Thanks for all the help with the dumb questions! I have been around boats for a long time just not boat maintenance! Haha

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[ColoradoDiablo]

No such thing as a dumb ? jet.
It only gets dumb when you don't ask a ?. Learn something new everyday is the way I look at it. If I have'nt learned something new , I haven't done a damn thing all day!
Which some days..........that's OK too!