symptoms of bad bellows

7 Symptoms Of Bad Bellows That You Need To Look Out For


Bellows are gaskets that are flexible and crucial for engine safety. Your boat engine stays protected because of the bellows. Technically, bad bellows can possess a potential risk to your boat engine. 

What are some of the symptoms of bad bellows?

The primary symptom of bad bellows is water leakage. Bad bellows can also stop your engine from working smoothly. Other than that, your boat may sink a little after staying docked for hours. Bad bellows can also cause loud noises, rusting, overheating, dry rotting, etc. 

Anyways, that was a summarization of multiple symptoms lumped together. Obviously, that may not be enough for many of you. 

That’s why we’ve listed the symptoms and had them simplified for you. 

Do Bad Bellows Possess Threats Towards Your Boat?

Before we jump to the main discussion, let’s talk about the bellows first. Bellows are often overlooked despite being extremely vital. 

Understanding the importance of a component can change your perspective about a matter. For instance, to prevent problems with Stratos boats, you’ll need basic knowledge about it. 

Bellows are gaskets that keep water from entering the boat engine. This alone makes bellows a super important component. 

You can say bellows act like protection to your boat engine. There are many advantages and disadvantages of bellows

But there’s one thing that people often wonder, can bad bellows sink a boat? 

Yes, bad bellows can potentially sink a boat. In fact, BoatUS, an association for boat owners claim bellows can sink a boat. They’re the 2nd most prominent reason behind boats sinking at the dock. Bad bellows create water intrusion. When too much water comes in, the boat can sink. 

As you can see, the bellows are super important for your boat’s safety. By knowing the symptoms of bad bellows, you can avoid dire circumstances. 

7 Signs That Indicate Your Bellows Have Gone Bad

In the previous segment, we’ve mentioned how bad bellows on boats can create problems. While you can’t stop a bellow from going bad but you can save your boat. 

Being aware of symptoms is helpful and always gives you an edge. It’s easy to deal with outboards by knowing the symptoms of bad trigger outboards

That’s why we recommend you go through all the symptoms one by one. By doing that, you can easily avoid a potential disaster. 

On top of that, the only fix for bad bellows is to replace them. If you detect any of these symptoms in your boat bellows, replace them immediately. 

Symptom 1: Bad Bellows Cause Water Leakage

We have already talked about this earlier in the discussion. But this time let us show you how you can easily guess the bellows are bad. 

To know whether your bellows are good, simply pull out the hatch. After pulling the hatch out, you may see water in the bilge. 

This can happen due to many reasons. For instance, the bow wall of the bilge can be cracked. That’s why you will have to rule the possibility out by yourself. 

For this, you’ll have to clean the bilge first. After that, take the boat to the open water and reopen the engine hatch. 

If you see water again, this is possibly due to the bad bellows. If that happens, the only option is to replace the bellows. 

To help you out, we’ve had our experts recommend their best picks-

U-Joint Bellows
Shift Bellows

You can pick whichever fits in your boat and get started!

Symptoms 2: Bad Bellows Can Interrupt the Engine

Other than water leakage, you should look out for your engines. Because bad bellows can interrupt the engine’s functions. 

You may notice that your boat engine is hesitating when starting. You can also find out that it requires a harder start than usual. 

If you see any kind of unusual engine noises, it can be due to bellows. 

Symptom 3: Bad Bellows Can Cause Loud Noises 

The loud noise issue is primarily a U-joint issue. If the bellows have gone bad, you might hear loud noises. These noises usually come from the back. 

To test this symptom, take the boat to the water. After that, try turning the boat. If the U-joint bellows have gone bad, you’ll hear louder noises. 

Simply replace the U-joint bellows to get out of this problem. 

Symptom 4: Engines Can Overheat Due to Bad Bellows

Like water leakage, noises and bad engine starts, overheating is also a common issue. We’ve already discussed that bad bellows can cause water insertion. 

If the water has entered, it will interrupt your engine’s cooling system. And when that happens, the engine will start overheating. 

That’s why overheating of the engine is a great sign that you shouldn’t ignore. 

Symptom 5: Bad Bellows Can Make Your Boat Sink 

This is one of the major signs that your bellows may have gone bad. After docking the boat, it’s possible for your boat to sink.

It wouldn’t totally sink under the water obviously. But you’ll notice that the boat isn’t completely floating. It’s actually a couple of inches down in the water. 

When that happens, you’ll see that water has seeped through the cracks. The bilge will be collecting water. And that happens due to bad bellows.

You can easily locate the bilge pump on the boat. Simply check it and see whether it’s fine or not. 

If you notice anything like this, immediately replace the bellows. 

Symptom 6: Bad Bellows Can Cause Rusting & Dry Rotting

Bad bellows to allow water into the engine. That’s why looking for rust signs or dry rotting signs is a smart idea. 

Open up the engine and look for the bearings. If the water has contacted the bearing grease, there will rust around. 

And that’s a good way to tell that you have bad bellows. Other than that, dry rotting is also a great sign. 

Symptom 7: Bad Exhaust Bellows Creates Unpleasant Odor

This symptom is more associated with the exhaust bellows. An unpleasant smell coming out from the engine indicates a strong bad exhaust bellows symptoms

If the exhaust bellows are bad, it will cause water to get in the exhausts. The fuel then gets mixed with the water. This fuel then burns and spreads a bad smell. 

Simply replace the exhaust bellows and you’re all great. 

These were some of the important symptoms that you should look out for. Overall, you can always avoid bad bellows problems by maintaining your boat properly


How often should bellows be replaced?

Bellows should be replaced about every two years or so. It’s because they’re extremely important and they’re the ones who prevent water leakage. You should also inspect the bellows regularly and look for cracks. Bad bellows can destroy your boat engine over time by allowing water. 

How long does it take to replace the bellows?

Replacing the bellows only takes 30 minutes or less. They’re fairly easy to remove and reinstall. The optimal time to replace the bellows is after a long session. Because then you’ll be able to tell that the bellows have gone bad. If there’s water inside the engine, it’s time to replace the bellows.

What can I use for bellows adhesive?

There are many bellows adhesives available online that you can use. These adhesives are resistant to oil, grease, and water. Because of that water, oil and grease can’t loosen the seals of the exhaust or u-joint bellows. They’re also fairly cheap on websites like Amazon and easy to apply.

Take Away 

That was everything we could explain and deliver on symptoms of bad bellows. We hope that these symptoms have given you some insights about the bellows problems. 

Also, check whether the exhaust pipe comes out of your boat or not. The pipe will hang downward and that implies possible damage to the exhaust bellows. 

Finally, have a nice day.

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