Mercruiser Exhaust Bellows

[hardworking]

Merry Xmas all,

So today I was out giving the boat the once over as we have friends coming down and we are planning on an outing, and I noticed that the exhaust bellows are split. A couple of big splits to be precise.

That said, I have read that they can be left completely off, but can anyone confirm?

It will sure ruin these next few days if we are beached.

Any help is much appreciated.

Cheers
J

[brett62]

Mate you will sink. Water will come right into the boat.

[hardworking]

Hmm serious. I am reading lots of guys running without it. I was out in it last week, and going by the split, it's been there's a while.

Do you have fist hand knowledge of this??


Would seem a little surprising that a length of flexi tube like that could sink a boat - but I am open to people experiences.

[Red October]

You will definitely get water in your boat with a split bellows. Perhaps more importantly the ingress of water into the bellows will cause failure of the gimbal bearing. This results in noise and vibration on turning the drive when steering. If the bellows has been damaged for some time you will probably already have damage to the gimbal bearing necessitating immediate repair.

[hardworking]

Hi red. No not the drive bellows. Only the exhaust bellows.


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[Noelm]

If everything is OK, the boat won't sink, but salt water will get we're it shouldn't.

[hardworking]

Yeah. Been doing some reading and most are relaxing the exhaust Bellows with what the call an exhaust tube. It's just a short length of rubber that only gets connected at the stern end and in the drive end. Only bi product is a little more noise.

Am going to see if I can inspect the drive bellows and start plans now to pull the drive and replace them all. Main use is on fresh water, but will get it fixed.


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[brett62]

[QUOTE=hardworking;1605912]Yeah. Been doing some reading and most are relaxing the exhaust Bellows with what the call an exhaust tube. It's just a short length of rubber that only gets connected at the stern end and in the drive end. Only bi product is a little more noise.

Am going to see if I can inspect the drive bellows and start plans now to pull the drive and replace them all. Main use is on fresh water, but will get it fixed.

Mate good idea. My reasons for the comment is if they are stuffed there is a good chance all are. While you have it apart check the water intake in the transom bracket if your water pick up is through the leg. If your sea water pick up is through the hull all would be good the plate on the bracket would be closed off. Just had my drive out and she was not far off completely closing off. The big problem is you need to remove it all to see if it's an issue, so a bit of work. I also found the bottom of the Y pipe was corroded with about 2mm left before the sea would join me in the boat. This was where the pipe bolts on down at the transom bracket.

Hope all goes well for you and don't find some of the issues I found. If you are using in fresh water mainly you may be ok. Salt water is a little less forgiving as you know.

[hardworking]

Thanks Brett. Have watched quite a few vids on pulling the drive and it doesn't look that hard to be honest. So I will order a full service kit and swap it all out. I will feel better knowing it's all done. If the bearing is gone, I will replace that too.


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[BM]

Earlier drives didn't have a bellows that was clamped at each end. It was a solid rubber tube mounted to the transom plate and as the leg trimmed down it slid over the rubber tube.

Yes you need to repair the bellows but it can be run as it is. Salt water (and exhaust) comes out the bellows in any case so some salt water leaking back in won't harm anything. The exhaust has a flapper valve installed to stop salt water surging back up the system.

Easiest test for gimbal bearing is turn the steering hard over and with the boat underway you will hear a click click noise like a front wheel drive car with shot universals. Alternately, with the drive removed stick your fingers in the gimbal bearing and rotate it to see if it's smooth (just like checking wheel bearings). You will need a slide hammer puller to remove the gimbal bearing and you can buy the replacement from a bearing shop for a fraction of the cost of the Mercury labelled part.

Removing the drive is very easy. Make sure you are in forward gear before removing or you can break the shift shoe.

[hardworking]

Thanks BM. Good info there.

I have had a good look (as much as I can) and the drive bellows looks good. Actually looks newer than the exhaust bellows. . I have only had the boat for 6 months and surprisingly this did not get picked up when I had it inspected prior to purchase. I think it's been split for a while.

Is there a way to test the gimbal bearing with the boat on the trailer? Bugger it. Might just replace it anyway. Give the whole arse end a service.

A couple of other questions...

I noticed that the bung plug is connected with a wire to a rubber hose, and I can pull that hose out the drain hole and its connected via a brass type connector on the hose. Can I ask what that is??

And lastly I have two hoses. Block drain and manifold drain connected to an easy release system. Is that just to drain them after each outing? Trying to find info on this but can't seem to find what I'm looking for.

Cheers
John.


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[BM]

I'm not following you about the bung plug. Maybe post up some pics?

The block and manifold drains are really a storage type thing. If you flush the boat with fresh water you don't need to drain it but if it "floats your boat" pun intended then drain it each time!


The he test I mentioned for the gimbal bearing is better under load but it can still be tested the same way on a trailer. But if you intend to remove the leg then check it with your fingers when the leg is off. A quick rotation one way then the other will tell you immediately if it's smooth or otherwise.

[Fed]

Look like this?
http://www.amarket.com/imD042M.HTM

[hardworking]

Ahh!!! I never thought of oil drain hose. Not exactly like that but I think you are right.


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[hardworking]

Hey lads,

Took the Sea Ray out all day yesterday on the lake and it performed well. No water in the boat at all - the kids had a great time tubing etc.

I have to do a bit of research now about prop and size etc. Paperwork shows the prop was swapped a little while ago and I want to make sure its the right size and pitch.

Cheers all and thanks for your help on this.

Cheers
J