WARNING- According to a yanmar parts dealer he exhaust elbow on yanmar engines is "disposable" and lasts approximately 3-5 years. Of course one must learn this kind of thing the hard way... After doing some engine work requiring disconnection of the high pressure fuel pipe while trying to bleed the lines a friend releases the compression on the aft cylinder and sea water immediately comes pouring out of the air intake. It took a few days to figure out what was going on. Apparently the air exhaust and sea water join at the mixing elbow and are pumped out together. Inside the elbow they are divided by a steel (not stainless) divider. Apparently the divider had rusted through allowing the water to back up through the air exhaust which is run below the water exhaust allowing gravity or any other simple forces to completely ruin your engine. My elbow looked fine from the outside. If I were you, I would remove the elbow and attached air exhaust piece attaching it to the block(attached by only 4 bolts) and examine it. If there is severe corrosion inside, I would replace it. Part cost me 170 which I would pay with a smile if I were not facing a total rebuild. I never had any trouble at all with my engine prior to this, It must be a freak incident but could easily happen to anyone else out there.
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Bob Keller
Yanmar School
I recently attended a basic Yanmar course at Mack Boring in NJ and yes your are correct. One of the items that the instructor stressed was to replace the elbow at no more than five year intervals. Good luck on your repair.
I recently attended a basic Yanmar course at Mack Boring in NJ and yes your are correct. One of the items that the instructor stressed was to replace the elbow at no more than five year intervals. Good luck on your repair.
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Joe
Fun Day?
I found out the hard way too. On a beautiful June day this year the wind started to kick 25-30k+. I had to motor out a channel about one mile into the wind. The engine over heated and I ended up on a sandbar and of course we had a boatful of guests. We did eventually get back to our home port (after much stress) and I discovered the mixing elbow to be clogged with rust. Never had any problems or other warning it was clogged.
I found out the hard way too. On a beautiful June day this year the wind started to kick 25-30k+. I had to motor out a channel about one mile into the wind. The engine over heated and I ended up on a sandbar and of course we had a boatful of guests. We did eventually get back to our home port (after much stress) and I discovered the mixing elbow to be clogged with rust. Never had any problems or other warning it was clogged.
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Merrill Mant
Salt or Fresh
I am sure that our 10 year old Yanmar has never had the exhaust elbow changed. What maintenance schedule would apply for fresh water boats that spend 6 months on the hard?
I am sure that our 10 year old Yanmar has never had the exhaust elbow changed. What maintenance schedule would apply for fresh water boats that spend 6 months on the hard?
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Terry
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Dick McKee
Where did you find an elbow for $175. For the
4JH2E in our 430 its is $480.00. If what they are telling you is correct, Yanmar is saying we should set aside $1.00 per hour we run the engine just for exhaust elbow maintenance. Seems a little extreme. Dick McKee S/V Constellation
4JH2E in our 430 its is $480.00. If what they are telling you is correct, Yanmar is saying we should set aside $1.00 per hour we run the engine just for exhaust elbow maintenance. Seems a little extreme. Dick McKee S/V Constellation
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Mark
Mine recently failed
I own an '81 37C and recently had my elbow fail. While motoring heard an abrupt change in pitch. A quick inspection revealed an exhaust and water mixture leaking from the mixing elbow. Being that we were 25mi from home and the cold front that spawned the tornadoes across the midwest this fall was fast approaching, I continued to motor for about 30 minutes to avoid having to beat into a 25kt breeze. We were then able to turn and had a close reach the rest of the way. When restarting the engine to enter the marina the exhaust/carbon fumes in the cabin were much worse - we couldn't even see the bottom of the companionway steps from the cockpit. Needless to say it was a big cleanup. Luckily I was planning to replace my cabin cushions this winter anyway - not sure it the smell would have ever come out. Inspection of the mixing elbow revealed a 1 inch diameter hole where the seawater mixes with the exhaust. I have a 3QM30F which has a 45 deg shaped elbow. I'm guessing this was orignial - 20 years. Of note: Last spring I had inspected the mixing elbow due to cooling problems which turned out to be an intermittent problem with the SW impellor. The elbow wasn't the least bit clogged - I didn't think to inspect for wall thickness. A new elbow cost $161 from Torresen Marine Parts found on the internet. The only problem was there were not in stock and had to be shipped from Japan. They said it would take 6-8 weeks, but showed up within one month. I'm glad the failure occurred on my last planned trip of the season! New elbow installed and tested - Now I just have to finish making the new cushions before spring! Mark
I own an '81 37C and recently had my elbow fail. While motoring heard an abrupt change in pitch. A quick inspection revealed an exhaust and water mixture leaking from the mixing elbow. Being that we were 25mi from home and the cold front that spawned the tornadoes across the midwest this fall was fast approaching, I continued to motor for about 30 minutes to avoid having to beat into a 25kt breeze. We were then able to turn and had a close reach the rest of the way. When restarting the engine to enter the marina the exhaust/carbon fumes in the cabin were much worse - we couldn't even see the bottom of the companionway steps from the cockpit. Needless to say it was a big cleanup. Luckily I was planning to replace my cabin cushions this winter anyway - not sure it the smell would have ever come out. Inspection of the mixing elbow revealed a 1 inch diameter hole where the seawater mixes with the exhaust. I have a 3QM30F which has a 45 deg shaped elbow. I'm guessing this was orignial - 20 years. Of note: Last spring I had inspected the mixing elbow due to cooling problems which turned out to be an intermittent problem with the SW impellor. The elbow wasn't the least bit clogged - I didn't think to inspect for wall thickness. A new elbow cost $161 from Torresen Marine Parts found on the internet. The only problem was there were not in stock and had to be shipped from Japan. They said it would take 6-8 weeks, but showed up within one month. I'm glad the failure occurred on my last planned trip of the season! New elbow installed and tested - Now I just have to finish making the new cushions before spring! Mark
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Craig
mixing elbow and exhaust elbow same thing?
i have a yanmar 3gm. i am looking at the yanmar operating manual. in there it has a mixing elbow but i dont see an exhaust elbow. are these two the same thing? the mixing elbow on my picture is here: if looking at the engine from the front it would be on the left rear corner up kinda high. it looks like 2-3 inches around and maybe a foot long. is this it? where should i buy one from? thanks. this is one of those things not to ignore. craig
i have a yanmar 3gm. i am looking at the yanmar operating manual. in there it has a mixing elbow but i dont see an exhaust elbow. are these two the same thing? the mixing elbow on my picture is here: if looking at the engine from the front it would be on the left rear corner up kinda high. it looks like 2-3 inches around and maybe a foot long. is this it? where should i buy one from? thanks. this is one of those things not to ignore. craig
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Robin
mastry
My yannie is (was) a 3gmf30. My exhaust elbow is a U shaped piece that according to my (nearly worthless) manual looks considerably different from your mixing elbow. I got the part from Mastry in St Petersburg FL. Ask for the "takeoff" exhaust elbow. Mention my name, and maybe that combined with the tons of money I will be spending there in the next few weeks might earn me some respect. http://www.mastry.com/
My yannie is (was) a 3gmf30. My exhaust elbow is a U shaped piece that according to my (nearly worthless) manual looks considerably different from your mixing elbow. I got the part from Mastry in St Petersburg FL. Ask for the "takeoff" exhaust elbow. Mention my name, and maybe that combined with the tons of money I will be spending there in the next few weeks might earn me some respect. http://www.mastry.com/
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Mark
Mixing/Exhaust Elbows the Same
Craig, Yes the Mixing and Exhaust Elbows are the same. It is the location in your exhaust line that the exhaust gases from the manifold mix with the SW cooling after going through the engine or heat exhanger. They are usually either u-shaped or a 45 degree elbow and vary greatly in price depending on your model. I purchased mine through the attached link. If you don't have a parts manual for your engine, you will need to call them to determine the correct part number. Mark
Craig, Yes the Mixing and Exhaust Elbows are the same. It is the location in your exhaust line that the exhaust gases from the manifold mix with the SW cooling after going through the engine or heat exhanger. They are usually either u-shaped or a 45 degree elbow and vary greatly in price depending on your model. I purchased mine through the attached link. If you don't have a parts manual for your engine, you will need to call them to determine the correct part number. Mark
2GM & 3GM mixing elbow.
I think you will find that the 2GM and 3GM elbow is the same part. I paid about $100 for mine. This included the gasket. It did not include the coupling. It is not a bad idea to purchase the new coupling. http://www.sailboatowners.com/upload/display.tpl?folder=Dion73065762803&fno=17 For those whos boats live in salt water the life of the elbow is almost indefinite. When a boat lives in saltwater the life is 3-8 years. The corrosion occurs from the sulfuric acid in the exhaust gases and saltwater mixture. Everyone should inspect this item every few years. You want to be sure that it is sound before replacing. If your has been on the boat for several years, I would recommend that you replace it. If the old one is still good, you can always save it for a spare.
I think you will find that the 2GM and 3GM elbow is the same part. I paid about $100 for mine. This included the gasket. It did not include the coupling. It is not a bad idea to purchase the new coupling. http://www.sailboatowners.com/upload/display.tpl?folder=Dion73065762803&fno=17 For those whos boats live in salt water the life of the elbow is almost indefinite. When a boat lives in saltwater the life is 3-8 years. The corrosion occurs from the sulfuric acid in the exhaust gases and saltwater mixture. Everyone should inspect this item every few years. You want to be sure that it is sound before replacing. If your has been on the boat for several years, I would recommend that you replace it. If the old one is still good, you can always save it for a spare.
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Craig
good website for this stuff
www.torresenmarine.com is an authorized yanmar dealer. they have a discussion board that addresses all these issues. you can do a search and up it comes and if you cant find it send them an email. craig
www.torresenmarine.com is an authorized yanmar dealer. they have a discussion board that addresses all these issues. you can do a search and up it comes and if you cant find it send them an email. craig
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Craig
Received comment from torresen marine
i sent an email to them about my mixing elbow and this is what they said: first off mixing elbow and exhaust elbow not exactly the same thing. the exhaust elbow typically attaches to the engine and it attaches to the mixing elbow. the fact that we have the tank ontop the engine for antifreeze makes us fresh water and because our engine is 1983 or after that makes us a 3gm30f and no zincs. the earlier ones are 3gmf with zincs they say because we sail exclusively in fresh water not to worry about the mixing elbow and says its problems normally revolve around salt water conditions. seem like nice people. i encourage you to check out their site at www.torresen.com hope this helps someone. craig
i sent an email to them about my mixing elbow and this is what they said: first off mixing elbow and exhaust elbow not exactly the same thing. the exhaust elbow typically attaches to the engine and it attaches to the mixing elbow. the fact that we have the tank ontop the engine for antifreeze makes us fresh water and because our engine is 1983 or after that makes us a 3gm30f and no zincs. the earlier ones are 3gmf with zincs they say because we sail exclusively in fresh water not to worry about the mixing elbow and says its problems normally revolve around salt water conditions. seem like nice people. i encourage you to check out their site at www.torresen.com hope this helps someone. craig
2GM20 or 3GM30 (no f)
Craig: Actually the only difference is that there is no 'F' on the raw water cooled models. The part that they refer to as the exhaust elbow is the exhaust manifold. This is what is bolted to the engine. I would agree that you would not normally need to worry about his part but I think it is a good idea to remove it and inspect it. It is an expensive repair in case of a failure.
Craig: Actually the only difference is that there is no 'F' on the raw water cooled models. The part that they refer to as the exhaust elbow is the exhaust manifold. This is what is bolted to the engine. I would agree that you would not normally need to worry about his part but I think it is a good idea to remove it and inspect it. It is an expensive repair in case of a failure.
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Richard Wallace
Changing The Elbow
Changing the elbow is not a big problem but there are a couple of things to know. It is easier to take the four bolts loose and take the exhaust manifold loose with the mixing elbow attached. That way you can use a vise to hold it. Get a new gasket before putting it back together. It is cheap insurance. The other important point is that the threaded coupler between the manifold and the elbow has one right handed thread and one left handed thread. It is made so that you could hold the elbow and the manifold stationary and turn only the coupler, kind of like using a turnbuckle. Unfortunately, if you don't know that or notice the difference in the threads, getting it apart can be quite difficult. (Wonder how I know that?) Mine is on a 1983 3GMF and it still appeared to be fine. Like the others, I saved the old one - just in case. No wonder you have to look at changing the waterline every year or two.
Changing the elbow is not a big problem but there are a couple of things to know. It is easier to take the four bolts loose and take the exhaust manifold loose with the mixing elbow attached. That way you can use a vise to hold it. Get a new gasket before putting it back together. It is cheap insurance. The other important point is that the threaded coupler between the manifold and the elbow has one right handed thread and one left handed thread. It is made so that you could hold the elbow and the manifold stationary and turn only the coupler, kind of like using a turnbuckle. Unfortunately, if you don't know that or notice the difference in the threads, getting it apart can be quite difficult. (Wonder how I know that?) Mine is on a 1983 3GMF and it still appeared to be fine. Like the others, I saved the old one - just in case. No wonder you have to look at changing the waterline every year or two.
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Michael O'
Ahhh, fresh water
After 15 years of use, I replaced my mixing elbow last year (just to be safe). There wasn't a hint of corrosion inside. However, my H31 is sailed only in the Great Lakes. The freshwater sea is very kind to sailboats! One word of caution about the removal process. With all those cycles of heating and cooling, it's not an easy job getting the elbow to come loose. Watch your knuckles!
After 15 years of use, I replaced my mixing elbow last year (just to be safe). There wasn't a hint of corrosion inside. However, my H31 is sailed only in the Great Lakes. The freshwater sea is very kind to sailboats! One word of caution about the removal process. With all those cycles of heating and cooling, it's not an easy job getting the elbow to come loose. Watch your knuckles!
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Robin
good news
Ive torn the engine down to the block and the pistons/ sleeves seem ok. Small amount of (what looks like) evaporated sea water on top of the aft piston. Crank shaft turns easily. Now I am thinking it is a valve problem and will proceed with replacing all of the gaskets, etc. Hopefully much cheaper of a job...
Ive torn the engine down to the block and the pistons/ sleeves seem ok. Small amount of (what looks like) evaporated sea water on top of the aft piston. Crank shaft turns easily. Now I am thinking it is a valve problem and will proceed with replacing all of the gaskets, etc. Hopefully much cheaper of a job...
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J. Tesoriero
Their disposable!
According to the Boat-Tech, product advice sections of the BOAT/US catalog, 50% of exhaust manifolds and risers on big gas engines or mixing elbows for our smaller diesels will experience failure within about 5 years, and 100% of them will fail after nine years. The heat, pressure and water just eats them up. It's not too big or bad of a job to remove and inspect the elbow every few years. It saves you everything from engine overheating problems to engine replacement.
According to the Boat-Tech, product advice sections of the BOAT/US catalog, 50% of exhaust manifolds and risers on big gas engines or mixing elbows for our smaller diesels will experience failure within about 5 years, and 100% of them will fail after nine years. The heat, pressure and water just eats them up. It's not too big or bad of a job to remove and inspect the elbow every few years. It saves you everything from engine overheating problems to engine replacement.
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