tackling the water heater on my 9.2A

Sep 15, 2009
6,243
S2 9.2a Fairhope Al
just clean them and use clean hose.... you can clean the hose by running a brush down them or some 120 grit sand paper on a dowel rod or a bolt
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
All hoses will be new, so that's no problem. I'll rub a little emory cloth over the rusty bits before slipping the hoses on.

Will use AWAB clamps on everything.
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
Had the same trouble pulling the water heater out of my Columbia 8.7. The old one came out fine with its cover removed, but I had to cut some fiberglass to get the new one in. Most builders put the big parts in before they install the deck.
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I've got the exhaust elbow out now and the boat didn't sink! At least not while I was there. I definitely need new exhaust hose. Only $13 a foot!

I'll upload a shot of the old elbow and the new, to show how the raw water exhaust port looks. Seems like maybe this maintenance was a bit overdue! Hard to believe the engine showed no signs of overheating prior to all this work.

Now I just need to figure out how to get the old exhaust elbow off the bushing. The little elbow that feeds the exhaust water into the big elbow came off easily enough, but I may be back to the machine shop to have them separate the big elbow from the bushing. I've got it soaking in PB Blaster currently, and will try some heat once I have my workbench vise area cleared enough to not immediately combust when I wave the mapp gas at it.

John
 

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Apr 27, 2011
423
S2 9.2A Newport News, VA
I gave up trying to separate the exhaust and mixing elbows. A new exhaust elbow wasn't all that much, so I ordered that and the bushing to connect them.

The repairs to the heat exchanger came to $210. I'll post some thrilling pics of its now-rejuvenated condition below. You can see, in the on-end shot, where they plugged the one leaking tube.

I'm down to ordering the new exhaust hose. The 16" piece from the mixing elbow to the muffler is clearly labelled 2", the ID. The hose from the muffler to the stern, which, with the loop, is probably close to ten feet long, is not clearly labelled and is definitely a bit smaller. Maybe a bit under 2" OD, close to 6" in circumference. I've been known to order the wrong size hose before (I'll be ordering wire-reinforced Trident exhaust/water hose) and, since this stuff isn't cheap, I don't want to make a mistake. I'll pull the longer hose off the muffler and check the ID, but does anyone know what it typically is on an '80 9.2A? It'd be nice to have my measurements confirmed.

John
 

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Apr 27, 2011
423
S2 9.2A Newport News, VA
Just back from the boat. I had to use a Dremel with a cut-off wheel to cut the wire-reinforced host from the outlet on the lift muffler (that was pretty smoky/smelly!). I measured the inside of the hose and the outside of the outlet and both look to be 1 1/2". No problem there; however, I noticed that the inlet side of the muffler had a piece of exhaust hose still on it, despite my pulling that hose off without cutting it. Apparently, a short piece of hose was put on the inlet to bring it up to the 2" ID of the Yanmar's exhaust. I suspect that isn't up to ABYC standards!

Is there another/better way to bring the 2" hose down to the 1 1/2" inlet? I didn't immediately find a source for a new muffler with a 2" inlet and 1 1/2" outlet.

Thanks.

John
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Just back from the boat. I had to use a Dremel with a cut-off wheel to cut the wire-reinforced host from the outlet on the lift muffler (that was pretty smoky/smelly!). I measured the inside of the hose and the outside of the outlet and both look to be 1 1/2". No problem there; however, I noticed that the inlet side of the muffler had a piece of exhaust hose still on it, despite my pulling that hose off without cutting it. Apparently, a short piece of hose was put on the inlet to bring it up to the 2" ID of the Yanmar's exhaust. I suspect that isn't up to ABYC standards!

Is there another/better way to bring the 2" hose down to the 1 1/2" inlet? I didn't immediately find a source for a new muffler with a 2" inlet and 1 1/2" outlet.

Thanks.

John
i replaced all my system with 2" hose ...new muffler ...new hose to the outside and a new through hull exhaust fitting all 2"...but you still have the small out let to the outside of the boat...i think centex makes an adapter/reducer for that...you will get better performance if you up grade to a 2 " in and out muffler and a 2"... long hose....the way it stands now you are sort of smothering that 2gm20f engine by having the 1 1/2 inch system but you can get by
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
i replaced all my system with 2" hose ...new muffler ...new hose to the outside and a new through hull exhaust fitting all 2"...but you still have the small out let to the outside of the boat...i think centex makes an adapter/reducer for that...you will get better performance if you up grade to a 2 " in and out muffler and a 2"... long hose....the way it stands now you are sort of smothering that 2gm20f engine by having the 1 1/2 inch system but you can get by
Yep. I thought you'd say that. I don't suppose I can change the opening exiting the hull to 2" with the boat in the water. I can probably trim the cut part of the old 1 1/2" hose and get it to work temporarily, then do the muffler and 2" hose when I next have the boat hauled, probably next summer.

John
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I checked and I can get a Centek 2" to 1 1/2" reducer for about $25. So, I'll probably go ahead and order that, the 2" x 2" lifting muffler, and all 2" hose. That'll do it until I can get the boat hauled. I will check with a local fiberglass guy and see if he wants to put the 2" hull outlet in with the boat in the water, but I suspect not.

John
 

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Sep 15, 2009
6,243
S2 9.2a Fairhope Al
I checked and I can get a Centek 2" to 1 1/2" reducer for about $25. So, I'll probably go ahead and order that, the 2" x 2" lifting muffler, and all 2" hose. That'll do it until I can get the boat hauled. I will check with a local fiberglass guy and see if he wants to put the 2" hull outlet in with the boat in the water, but I suspect not.

John
i put my new bronze outlet in the boot stripe on the rear and closed up the hole with glass and epoxy i am sending you a pm
 

BobM

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Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
I have to say that I just can't believe that a two inch exhaust is going to smother a piddling little 2 cylinder 20 hp diesel. There is a 2 inch exhaust on every car I own and some make 300 hp and some have 12 cylinders!
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
I have to say that I just can't believe that a two inch exhaust is going to smother a piddling little 2 cylinder 20 hp diesel. There is a 2 inch exhaust on every car I own and some make 300 hp and some have 12 cylinders!
in the first place that is what is recommended by Yanmar and your 12 cylinder auto is not restricted by a water lift muffler and i suspect that the exhaust mixing elbow is less prone to clogging with the larger size pipe and we know how aggravating that can be....and also i have to wonder why the big mercruiser inboards all seem to have 5 inch diameter pipes or larger and it only cost a nickel more to do it correct while he is in there ...you don't mess with propulsion when it comes to boating neither the engine or the sails do it right or you may spend some very disparaging days and nights on the water from short changing your self i am sure there are more reasons than what i have posted.....a good example of short changing one self is i recommended to a friend about 2 years ago to change the power steering belts on his Caterpillar powered motor home he didn't do that and he called me from some place in VA on the way back from NY he had lost steering and had to call the truck repair guy out to get him going$$$$$$$ dah
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I was wondering when Bob would "pipe up"! I think Woody's made a good point about the muffler and exhaust water adding a great deal of restriction. And as for the mixing elbow clogging, just take a gander at the shot I posted of mine a bit back. I'm surprised the engine didn't overheat.

I think I've mentioned before that this is most likely a replacement engine. I also suspect that the original was raw water cooled and that its whole system, from the exhaust manifold back, was 1 1/2". My poor little 2GM is rated at just 16HP, so, when I'm grinding my way back to the marina, agin the tide and wind and with the bottom typically not pristine, an extra HP would be nice to have, even if it's just in my head.

I think I've assembled all the gaskets, o rings, and hoses, and hope to get busy reassembling everything today. If anyone has any tips on putting it back together - particularly with regards to the heat exchanger - they'd be much appreciated. (It's just the cooling system I've dismantled, and the exhaust elbow stuff. I need to reassemble the split halves of the FWP, bolt it back to the engine, put in the new hoses, reinstall the HE, attach the new exhaust elbow and mixing elbow, and then probably reuse the old exhaust hose until I can get the new 2" thru-hull in.)The manuals (I'm mostly using the factory and Seloc ones) don't mention that there's any particular orientation for the HE. They mostly warn about clean surfaces and making sure you don't pinch an O ring or crush the HE tightening the bolts.

Any favorite gasket sealants?

John
 

BobM

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Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
Well, one Jag XJS with a V12, a 73 Charger with a a 340, a 64 Dart with a 273, a BMW 328 and my 06 Tundra. So one V12 at the moment and perhaps two with 300 hp.

Sorry Woody but I just can't see, viewing engines as air pumps, that a 25-30% increase in capacity is going to be a strain, but it is probably a deal breaker on a new engine warranty. Just a PITA to change the hole in the hull needless to say.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
John if you look close at the tube body you will see the pattern for the end caps and gasket when you see that then you will be able to see the orientation of the tube as for the sealant use any good permatex high temp compound that comes in the tooth paste style tubes
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Well, one Jag XJS with a V12, a 73 Charger with a a 340, a 64 Dart with a 273, a BMW 328 and my 06 Tundra. So one V12 at the moment and perhaps two with 300 hp. Sorry Woody but I just can't see, viewing engines as air pumps, that a 25-30% increase in capacity is going to be a strain, but it is probably a deal breaker on a new engine warranty. Just a PITA to change the hole in the hull needless to say.
not a problem bob theses little engines need all the help they can get
 

BobM

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Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
My little 2QM15 with its raw water cooling just keeps on ticking (fingers crossed)!
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Also the exhaust on the 9.2 is a piss poor design as it is below the water line with no way to stop water from coming in the boat if a hose should fail
 

BobM

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Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
I should take a hard look at my exhaust hose. I replaced the water intake hose, but not the exhaust. Should look at the muffler too.