Replacing Yanmar exhaust hose

[artboas]

I’m noticing small cracks on my H49 Yanmar exhaust hose. I get an “diesel smell.” In the aft cabin with the engine running, and suspect this might be exhaust gas through the cracks. The hose goes through a very tight loop above water line, and this might be accelerating the cracking. In any case, I don’t think that exhaust hose is supposed to have visible cracks

First thing.
Removing this hose is a horrible job to do alone. Getting it off the stern fitting wasn’t the worst, BUT, removing it from the water muffler was a class a pig of a job.
I’m the lucky guy with the washer dryer in the aft cabin.
And the water muffler is below the washer dryer.
Had to completing disassemble the cabinet in the stbd aft, and then pull the washer out in the stbd cabin.
This is a virtually impossible job out owing to wood trim with “invisible screws” that are installed from underneath the floor. Removing these 3 screws took a day, as I didn’t want to hack up the cabinetry.
Here’s my question

The exhaust hose is 3”. It was bedded into the muffler and exhaust with some sort of flexible putty under the hose clamps. Would this be normal pipe dope, or any other good ideas (other than 5200) Clearly, it needs to be removable (for the next guy), but I don’t want to use something unfit for purpose

Ideas ????

 

[Sailm8]

You might get a temp fix using muffler tape where the cracks are.

 

[Ralph Johnstone]

Hang on to your suspender 'cause this is really going to give you a belly laugh but I always coat the interior of the EX hose with Superlube at the joints.

I first became aware of this stunt when I was disassembling the hose to mixing elbow joint. Even after one year, I had to fight like hell to remove the hose with the elbow IN A VISE. "Nevermore" I wailed. I lubed it the first time with the elbow in the vise and double hose clamped and tried with everything I had to twist it off. No on your life. Undid the hose clamps and it slid off easily. Repeated the exercise and again "not coming off for love nor money." I now go for several years without removal (SS mixing elbow now) and there is definitely more friction but still comes off far easier than without the lube.

My joints on the muffler and elsewhere are out in the open so I can check them if and when I get around to it. They're all lubed but still no give. Your connections to the muffler are hidden under the dryer and you may want to ensure the hoses are clamped to solid a surrounding and compressed against the muffler just to be sure there is no danger of separating. Maybe install an official looking deck plate :

....................... just to ensure you all is well with the joints in there..

 

[artboas]

Hang on to your suspender 'cause this is really going to give you a belly laugh but I always coat the interior of the EX hose with Superlube at the joints.

I first became aware of this stunt when I was disassembling the hose to mixing elbow joint. Even after one year, I had to fight like hell to remove the hose with the elbow IN A VISE. "Nevermore" I wailed. I lubed it the first time with the elbow in the vise and double hose clamped and tried with everything I had to twist it off. No on your life. Undid the hose clamps and it slid off easily. Repeated the exercise and again "not coming off for love nor money." I now go for several years without removal (SS mixing elbow now) and there is definitely more friction but still comes off far easier than without the lube.

My joints on the muffler and elsewhere are out in the open so I can check them if and when I get around to it. They're all lubed but still no give. Your connections to the muffler are hidden under the dryer and you may want to ensure the hoses are clamped to solid a surrounding and compressed against the muffler just to be sure there is no danger of separating. Maybe install an official looking deck plate :

View attachment 221049

....................... just to ensure you all is well with the joints in there..

Thanks for this
So, this is basically Teflon grease or similar.. certainly ok with temperature.
I think Hunter used standard plumbing dope.. not going to leak with good hose clamps on it.

Getting to the water muffler was horrific. There is a removable floor plate, which is 100% accessible if you don’t have a washer dryer.
Had to remove the entire cabinet in the port rear cabin. I’m actually an expert at this, as you need to do this to access the rear of the washer. It’s an awful job!!

I’m going back to the boat tomorrow to try and actually get the hose out of the stern area. It is a long length, which is impossible to maneuver. I’ll probably call in replacements at some point to assist.
I believe that signs of cracking on an exhaust hose mandate replacement. I’ll try to find something more flexible than the original black hose, but I’ll not optimistic on this.

 

[Ralph Johnstone]

So, this is basically Teflon grease or similar.. certainly ok with temperature.

The only reason I recommend Superlube is that it is non-petroleum and unlikely to react with the EX hose. I use this on every type of hose I work with, hence the need for non-reacting synthetic grease.

 

[artboas]

The only reason I recommend Superlube is that it is non-petroleum and unlikely to react with the EX hose. I use this on every type of hose I work with, hence the need for non-reacting synthetic grease.

I’ve just gleaned on to Vetus exhaust hose called “Slang”
It’s supposed to be much more flexible than the trident or Shields.


Anybody care to weigh in on this ????

 

[Ralph Johnstone]

I’m going back to the boat tomorrow to try and actually get the hose out of the stern area. It is a long length, which is impossible to maneuver.

I wouldn't want to be accused of being cheap here but perhaps you could use the expensive "Slang" hose in the difficult areas between hose joints and the cheaper Trident hose in the easier areas, again between joints if it amounts to any considerable savings.

 

[artboas]

I wouldn't want to be accused of being cheap here but perhaps you could use the expensive "Slang" hose in the difficult areas between hose joints and the cheaper Trident hose in the easier areas, again between joints if it amounts to any considerable savings.

Thanks for this, but putting couplers into the hose is just risk I don’t need.
I think that the Vetus and Trident are very close in price. I was quoted $60/ foot (cdn) for the hardware hose, and the Vetus is about the same.
I’m going to switch over to “T bolt” hose clamps, which are much better than the crummy ones that Hunter originally installed. The screw-type hose clamps are ok on small diameter stuff, but need to really torque up the pressure on this hose. I’m more than willing to spend a few extra bucks on premium quality clamps. This is an expensive job, but a very necessary one. The good news is that I can (Barely), manage the install myself, so don’t need to spend big bucks on a pro.

I figured out a very cool way to get the hose onto the muffler. There is no easy way to force it on from the stern compartment. I’ll document with photos once it’s done.

 

[Ralph Johnstone]

I was quoted $60/ foot (cdn) for the hardware hose, and the Vetus is about the same.

Then it's just a case of bite the financial bullet. Looking forward to seeing the finished job, hopefully without the blood.

 

[artboas]

Then it's just a case of bite the financial bullet. Looking forward to seeing the finished job, hopefully without the blood.

Then it's just a case of bite the financial bullet. Looking forward to seeing the finished job, hopefully without the blood.

 

[artboas]

Ouch

 

[Ralph Johnstone]

I’ll document with photos once it’s done.

Lord tunderin' Jesus man.

You haven't even started yet and already it's a blood bath .

 

[dkinzer]

I replaced the 3" exhaust hose on my 2007 41AC last year. I didn't relish the thought of trying to wrestle that hose into a high loop at the through hull so I opted instead to purchase a Centek 180* fiberglass bend. They come in various sizes - the 3" size is #1200199.

 

[artboas]

I replaced the 3" exhaust hose on my 2007 41AC last year. I didn't relish the thought of trying to wrestle that hose into a high loop at the through hull so I opted instead to purchase a Centek 180* fiberglass bend. They come in various sizes - the 3" size is #1200199.

View attachment 221275

I did some homework, and found that the Vetus hose has a very acceptable bend radius. Had a discussion with Vetus, and they confirmed that the hose was fit for my engine. So, I’ve ordered it, and am waiting for delivery.
It was awful pulling out the original hose, and I thought about putting in an adapter. But, the Vetus seems to answer this problem
I’ll post results ….

 

[jssailem]

@artboas I just installed a 2” diameter Vetus exhaust hose in my boat. The flexibility is excellent. The hose resists kinking. It has 2 wires wrapping the hose. Makes it a bit of a challenge to cut square. It was easy to position in my boat.

 

[artboas]

@artboas I just installed a 2” diameter Vetus exhaust hose in my boat. The flexibility is excellent. The hose resists kinking. It has 2 wires wrapping the hose. Makes it a bit of a challenge to cut square. It was easy to position in my boat.

Thanks for this.
As far are cutting it square, I plan to use a mitre saw box with hack saw
Failing that, a Co2 laser
I think this hose will be ideal for the very tight stern compartment where a U bend is required.

I have a trick “uo my sleeve” for getting it onto the muffler . If it works , I’ll post for sure

 

[jssailem]

My stern tube connector was 50mm the hose slipped on with a little help.

 

[Ralph Johnstone]

If it works , I’ll post for sure

And if it doesn't ..................................

 

[artboas]

And if it doesn't ..................................

Ok, it worked ….
This was not an easy job.
Getting the original hose out was a brutal experience.
I got lucky, finding out about the Vetus hose. It is so much more flexible than the original stuff. It made the install a LOT easier.
But,,, I had a big problem to figure out.
The water muffler is under the floor below the washer / dryer. Removing it was not a joyful experience. If anyone has a washer /dryer on a 49/50, I have some important tips for you. One of them is that there is a totally inaccessible filter that needs to be checked and cleaned at least once per season . If you don’t do this, then you are looking at a shortened life sons of the unit. And,, there is no way of removing this unit from the aft cabin.
Once I had the unit out, I could see the muffler.
Seeing something, and being able to work on it are 2 different things.
Removing the hose ended up being a cut & hack procedure. I was very concerned on how I was going to force the new hose on, as there was no way to get hands on it to pull or push it.
Came up with an interesting solution which worked like a charm.
I tied a short rope to the hose with a couple of hitches.
I was then able to muscle the hose just to the point where the hose was centred on the muffler outlet.
I attached the hose to a one end of a ratchet strap unit , and secured the other end to a stationary point on the other side of the muffler
Then, I was able to slowly ratchet the hose all the way onto the muffler fitting with relative ease. There was absolutely no other way to do this .

I swapped out the rather under rated hose clamps with band claims with socket drive bolts. I highly recommend doing this when dealing with hose of such a large diameter. There is no way to adequately torque spiral screw hose clamps, and at $8 apiece, they are well worth the money.
So,, it’s done. My list is now one item shorter !

 

[Gary Ryan]

Looking forward to tackling this job in the spring....not.