Replacing Exhaust Hose on a 1980 30

richga

.
Jun 7, 2004
1
- - salem, ma
Been lurking on this site for years and wanted to thank everyone for the great ideas and solutions that have been posted. They have been appreciated. I've been searching on this site for the best way to replace the exhaust line from the engine all the way to the transom. I've removed the sinks and oven and the storage drawers in the galley. Not sure if the ice box needs to be removed. Can't see the hose running along there. But the one question I do have is regarding getting to the transom. Looks like I'm going to have to do this upside down (if I can fit through the small hatch). I've searched this site to see what others have done and couldn't find anything that addresses replacing the whole thing. I've put it off for a long while because it doesn't seem to be an easy replacement. Any thoughts or ideas from someone who has done this would be greatly appreciated. Thanks in advance.
 
Aug 16, 2009
1,000
Hunter 1986 H31 California Yacht Marina, Chula Vista, CA
First, I'm always curious about why folks are so secretive about their boats. If you want boat specific information, don't be afraid to tell us the make, year and model. Rant over. I've done this on my H31, but you're routing sounds different. It would have been a far worse nightmare attaching the stiff hose at the transom if I had not removed the fuel tank first.
 
Feb 26, 2004
22,752
Catalina 34 224 Maple Bay, BC, Canada
Richard, read the title, he did say Catalina 30!!!

richga: It's rather simple. It's a (most likely) 1 5/8" exhaust hose from the muffler to the transom. You have to do some dumpster diving to get to the transom, but they put that hose in so you could actually get to it and replace it.

I have a C34 and did mine a few years ago. It's a PITA but it can be done.

ITWMB, I'd simply Google in general or this site in particular (you know how to use site specific Google search terms?) and look for "Catalina 30 exhaust hose replacement."

Good luck.

Oh, here's how I did mine: http://c34.org/bbs/index.php/topic,6760.30.html

scroll down and page 4 for pictures
 
Aug 16, 2009
1,000
Hunter 1986 H31 California Yacht Marina, Chula Vista, CA
Right as usual, Stu. I normally log into "all discussions" so failed to note that Rich's post was made to the Catalina forum from which I could have figured out he had an 80 Cat 30. Looking at the pics Stu posted, I'm not sure whether the Hunter or Cat presents a bigger challenge, particularly at the transom. I used the wire reinforced hose and wrestling it onto the nipple behind the fuel tank would have challenged the dark side of my vocabulary.
 
May 20, 2015
7
catalina 30 mk2 Apollo Beach
As most who have had this problem, I discovered the cracked and weathered hose in the transom area thanks to a diligent pre purchase survey. From the posts I’ve read I did not expect an easy job of it, but the information I did find was at best incomplete, so this is my effort at being thorough.

See attached:View attachment Catalina 30 Exhaust hose replacement.pdf
 
Nov 7, 2012
678
1978 Catalina 30 Wilbur-by-the-Sea
I will be doing this myself next time out I get out to the boat.

finally got my motor functioning to discover the exhaust hose leaks cooling water and CO into the bilge. Lots of it. Set my co alarm off.

My muffler is 1.5" id on the out port so that is what I ordered, wire reinforced.

I do not think removal of the ice box is required but you most likely will have to climb down in the sail locker. My boat has a flapper/check valve there.

https://svknotaclew.files.wordpress.com/2015/06/img_0659.jpg

I imagine it will take some work to route it around the icebox, I may have to climb into the galley drawer are. Its it tight but doable as I have already replace both my waste line and fuel fill hose which run the same general path.

The real worry I have is attaching the hose to the transom thru hull. I replaced a broken thru hull for our bilge pump and that area behind the rudder shaft is a bear to work in. Access on our 78 was via a small hatch at the rear of the quarter berth.
 
May 20, 2015
7
catalina 30 mk2 Apollo Beach
Good luck!

There seems to be some differences in the 80 model from the 91 but removing the ice box is not an option. I'm not sure the round trunkway behind the ice box is in the older models. I would consult the owners manual on that check valve. Adding any resistance to the exhaust of a diesel motor will effect motor performance, since the through hull is well above waterline and has a clapper on it; the check valve is redundant and an unnecessary failure point added to the system. Additionally the run along the port lazarette runs under the gunnel forming a loop seal aft further isolating any water ingress through the flapper. If you do not have a flapper on your through hull I strongly recommend one.
 
May 20, 2015
7
catalina 30 mk2 Apollo Beach
I did remove the draw set inboard of the ice box but other than giving a view of some unrelated hoses it did not help on the exhaust hose job. I wanted to overhaul my ice box foot pump so it was not a total waist. Unlike the waist and fuel line the exhaust bends fwd right below the transition in from the lazarette, no doubt to keep as much as possible above the waterline. The 78 model may be different in that way but I doubt it.
 
Nov 7, 2012
678
1978 Catalina 30 Wilbur-by-the-Sea
Mine goes forward thru the lazerette bulkhead and has a loop down under the ice box that almost goes as far as being below the drawer set, it then loops back up under the stove to the motor compartment. I may alter this when I run my replacement hose.

I plan on taking the check valve apart and see if it is functional. Will reuse it if I can as it also acts as a nice junction. My boat was a diesel boat before someone pulled it and did the outboard thing, I think the exhaust is factory.
 
Oct 18, 2019
7
Catalina 30 Alameda
I ordered 21' thinking it would be way more than enough, do you think 23' are required?
 
Nov 7, 2012
678
1978 Catalina 30 Wilbur-by-the-Sea
Well I ordered 25' when I did mine. still have 3 or 4 feet scrap in the garage.

I would run the check valve to motor first and if you come up short it will be the shorter run you will have to order.
 
Oct 18, 2019
7
Catalina 30 Alameda
Is the loop necessary? I don't think mine had a loop but I can't really tell because they filled the whole area with foam which is a an absolute nightmare
IMG_20191019_125700.jpg
 
Nov 7, 2012
678
1978 Catalina 30 Wilbur-by-the-Sea
no loop in mine. Getting around the cooler was a bear, I ran a string and laced it around the end of the hose. Did not have the foam,. probably a gift of a previous owner.
 
Oct 18, 2019
7
Catalina 30 Alameda
no loop in mine. Getting around the cooler was a bear, I ran a string and laced it around the end of the hose. Did not have the foam,. probably a gift of a previous owner.
I'm thinking of just leaving the old hose there, clearing enough foam to get the new one in, is there anything wrong with that?
 
Nov 7, 2012
678
1978 Catalina 30 Wilbur-by-the-Sea
I'm thinking of just leaving the old hose there, clearing enough foam to get the new one in, is there anything wrong with that?
Not that I can think of. You may want to just remove the corner countertop over the cooler if it all gets to be too much from underneath. A lot of work either way.
 
Nov 7, 2012
678
1978 Catalina 30 Wilbur-by-the-Sea
Is that behind the icebox under the counter?

My only thought would be to get a piece of schedule 40 a hair larger than the hose and use it as a bore to cut through the foam. problem being would be to get it at the correct angle.
 
Oct 18, 2019
7
Catalina 30 Alameda
I've just been cutting holes along below the counter and using a flathead and my hands slowly working foam out, I'm going to need to drill a new hole for the new hose though as the angle would be too much, so instead of coming straight up out of that area it will come out sideways.