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Yanmar mixing elbow again...with a twist


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Last Saturday was to be our first outing since Thanksgiving, Covid and all that shit. Got down to the boat, went through the usual pre sail check of systems, this always includes firing up the engine and allowing it to run long enough to be sure there won't be any surprises. So, out of the slip, down the fairway, hoist the main and we're off. Well we get to the turning basin and the engine sort of falters, I leave the helm to my crew to go below to check and discover SMOKE!, and about 2 gallons of salt water in my normally dry bilge. Call to shut down the engine, now sailing I called for a tow.

Back in the slip, engine panels off the issue is reveled to be the exhaust system has shit the bed.

Now I start to research how challenging and expensive the  replacement is going to be on my 3QM30 which is at least 30 years old.

So I discover HDI Marine Stainless Steel Exhaust - HDI Marine20210408_104714.thumb.jpg.558105ff85f535bfb642c11ff18c6686.jpg   

To my delight. They manufacture replacements for a  range of engines including mine. Great costumer service in helping me order the correct kit and delivery in 3 days with standard shipping. and under $300.00

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"now sailing I called for a tow."

I for some reason cannot reconcile this statement. Have sails, yet need a tow?

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49 minutes ago, blunted said:

"now sailing I called for a tow."

I for some reason cannot reconcile this statement. Have sails, yet need a tow?

Umm, stalled engine, smoke and water from an unknown source, narrow fair way and slip. Blunted, fuck off

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If anyone is interested in what a Yanmar elbow looks when the engine barely runs. 

Elbow.jpg

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2 hours ago, DrewR said:

If anyone is interested in what a Yanmar elbow looks when the engine barely runs. 

Elbow.jpg

Is that when the engine can barely run or when it's rarely run?

Asking for a friend.

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On 4/9/2021 at 10:16 AM, Malaya said:

.....

So I discover HDI Marine Stainless Steel Exhaust - HDI Marine   

To my delight. They manufacture replacements for a  range of engines including mine. Great costumer service in helping me order the correct kit and delivery in 3 days with standard shipping. and under $300.00

+1 to HDI Marine.  Had the exhaust scale / carbon buildup on my J/109 3YM30 and it looks exactly like yours.  Another friend has the 3GM30 with the same replacement.  There is a post with pictures on the J/109 forum.  The stainless replacement makes much better sense than a carbon steel OEM part.

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Wow. I had no idea the designers made elbows that restrictive. Even factory fresh that would be quite restrictive. But diesels are good pumps so maybe it doesn't affect power much???

That elbow looks sound. Could it have been cleaned out? Impossible?

We need to do more preventative inspection and maintenance on our engines...

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On 4/10/2021 at 10:19 AM, justsomeguy! said:

Is that when the engine can barely run or when it's rarely run?

Asking for a friend.

The engine surprisingly ran fine but overheated when run WFO. When I sliced it open at work, I couldn’t believe the engine ran at all. I too went with the same stainless elbow mentioned above. 
 

1/2 of my mess was given to the boatyard general manager to use as a visual aid for customers. 

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I could not even begin to tell you how many mixing elbows I have changed on my 2QM15 Yanmar from 1978. At least it is somewhat accessible. Not sure I am up for another one, but if I am it will be the stainless one, wish I had know about it before.

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The elbow on my 3QM30 broke about 20 years ago.  My doesel mechanic mate made a new stainless one - cost me $700 way back then!  Still going today, so I guess it was worth it.  Current boat has a 2QM20, so I'll bear this mob in mind - thanks Malaya.

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I have replaced three mixing elbows, all were choked solid with deposits. None of them had any visible corrosion issues, so I went with a cast iron elbow again a couple of weeks ago. I really don't see how the stainless elbow is much of a bonus when they clog instead of rot.

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When they are simply clogged with deposits can't those be removed by boiling them in an engine builders hot tank?

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3 hours ago, SloopJonB said:

When they are simply clogged with deposits can't those be removed by boiling them in an engine builders hot tank?

Someone must have tried. I know it's impossible to clean one by any means I had available.

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I thought if I just tossed in the back of my pickup for a few days/weeks it would help to clean it out, no did not help. The inside finish is not smooth, its even rougher than the outside. I called Yanmar and asked if could use a higher temp thermostat in the cooling system after I installed the FWC on the 2QM15. They said ABSOLUTLY NO! Because the engine was designed to run at 135 degrees, any higher would mess with the clearances etc. One thing I found that can help is to remove the nipple on the elbow where the cooling water dumps in and run a stiff wire into the elbow to help clean it  out, even that is a temporary situation. I just hate changing that mixing elbow. I even took a on of my old mixing elbows to an old fashioned radiator shop to "boil it out" but they declined as they did not think material of the elbow would survive.

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Heavy cast iron won't survive in a tank that sheetmetal radiator parts survive in?

They just didn't want their caustic polluted with the crud would be my guess.

Try an engine shop hot tank - same sort of thing but they do cast iron all the time.

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11 hours ago, Big Bob said:

I thought if I just tossed in the back of my pickup for a few days/weeks it would help to clean it out, no did not help. The inside finish is not smooth, its even rougher than the outside. I called Yanmar and asked if could use a higher temp thermostat in the cooling system after I installed the FWC on the 2QM15. They said ABSOLUTLY NO! Because the engine was designed to run at 135 degrees, any higher would mess with the clearances etc. One thing I found that can help is to remove the nipple on the elbow where the cooling water dumps in and run a stiff wire into the elbow to help clean it  out, even that is a temporary situation. I just hate changing that mixing elbow. I even took a on of my old mixing elbows to an old fashioned radiator shop to "boil it out" but they declined as they did not think material of the elbow would survive.

The first elbow I encountered was plugged at the water inlet and a stiff wire didn't do a thing. I finally had to drill it out and even that took some work. Got me an extra year, though.

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Engine block boiling treatment might be useless because the seawater scale is different than automobile scale. The silicon in seawater might be the culprit. It permeates the softer calcium and magnesium deposits. Insoluble: resists acid, alkali, and hammers (think granite).

Best solution is regular inspection. Hmmm...I'm at ten years and a thousand hours...maybe I'll do that...

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2 hours ago, Borracho said:

Engine block boiling treatment might be useless because the seawater scale is different than automobile scale. The silicon in seawater might be the culprit. It permeates the softer calcium and magnesium deposits. Insoluble: resists acid, alkali, and hammers (think granite).

Best solution is regular inspection. Hmmm...I'm at ten years and a thousand hours...maybe I'll do that...

I figure 1000 hours is time to seriously think about replacing it. We got 1100 hours on the last one I think, maybe a bit more. But I knew it was time.

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Have a raw water cooled VP 2003, notorious for blocked mixing elbows. They are cast iron.

So I have a few old spares, I have found that sealing the ends and filling it with 50% HCl for a day or so works well, and doesn’t seem to wreck the elbow unless it is already very porous.

 

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I just had mine break on me. It actually busted at the joint between the manifold and the elbow.

I had gone down below for a snack 1 hour into our cruise and I smelt smoke. Quickly looked in engine bay to see a little bit of water spurting out. Had my friend turn down the rpms and boom the thing blew out. We turned away from shore and got some distance with the sails up to shut down and access the situation. We hobbled back to port by duct taping it together and having my friend stand on the engine cover to apply pressure to the broken connection. The duct tape actually held out for a lot longer than I anticipated and we made it back fine. The whole time I was watching that water was making it's way out the stern. 

When removing the old part it just broke. not much we could do with it. So now I've had to clean up the threads with a screwdriver/chisel.  

IMG_3589.jpg

IMG_3599.jpg

IMG_3601.JPG

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This is the elbow side which was harder to clean up. The threads are pretty beat but I'm gonna try it with some anti seize/sealant to make it work. 

IMG_3616.jpg

IMG_3617.jpg

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There's a reason that Red Green called duct tape "The Handyman's Secret Weapon".

It's the 21st century equivalent of baling wire.

By the way, I find Gorilla brand to be superior to any other - even 3M tape.

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2 hours ago, Ishmael said:

Gorilla tape crawls too much in the heat and leaves a shitload of residue. This is the best.

 

I will definitely buy this stuff when I install my light water fission reactor onboard. 

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1 hour ago, retroSail said:

I will definitely buy this stuff when I install my light water fission reactor onboard. 

Don't forget to spray sunblock on your jib before firing it up.

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