All black pipe parts: 1 1/2 inch tee $3.59 1 1/2 inch close nipple - $.79 1 1/2 inch street elbow - $2.99 1 1/2 inch x 1 inch double tapped bushing - $7.19 1 inch x 1/2 inch bushing - $.99 1 inch x 3/8 inch bushing - $1.59 1/2 inch x 6 inch nipple - $.99 3/8 inch plug - $.59 sales tax - $1.50 total $20.22 Having a mixing elbow that I can inspect and fix easily, inexpensively, and avoiding the marketing geniuses and pirates of the Yanmar supply system - PRICELESS
Mixing Elbow - Home Depot Method
- Thread starter patrick
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impressive, but
Seems impressive! I will wait for others to comment. If it is as good in reality as you say, I will be quite impressed. ..waiting for others to reply. but thanks. joe
Seems impressive! I will wait for others to comment. If it is as good in reality as you say, I will be quite impressed. ..waiting for others to reply. but thanks. joe
Forgot one part
1 1/2 inch x 6 inch nipple $2.00 with tax new total $22.22 Works ok so far. Ran full out for an hour and it was very good. Got 3200 rpm under way and 3700 no load maximums. These are increases of 200 rpm loaded and 500 rpm no load speeds. The center of the tee got fairly hot but idling for a minute or two and I could touch it with my hand. Time will tell. I am going to get a set of schedule 80 fittings for spares and keep a close watch on this part. After my experience with the Yanmar part, I am convinced that this part should be removed, cleaned and inspected every couple of years as part of normal maintenance.
1 1/2 inch x 6 inch nipple $2.00 with tax new total $22.22 Works ok so far. Ran full out for an hour and it was very good. Got 3200 rpm under way and 3700 no load maximums. These are increases of 200 rpm loaded and 500 rpm no load speeds. The center of the tee got fairly hot but idling for a minute or two and I could touch it with my hand. Time will tell. I am going to get a set of schedule 80 fittings for spares and keep a close watch on this part. After my experience with the Yanmar part, I am convinced that this part should be removed, cleaned and inspected every couple of years as part of normal maintenance.
Ron -
A mixing elbow is also called an exhaust riser. It is the inverted "U" shaped fitting on the end of the exhaust system. It has a passage where the raw cooling water is mixed with the exhaust gasses. That is for the purpose of cooling the exhaust before it is passed into the rubber exhaust hose. Mine has been a source of problems since I got this boat. It is poorly designed and therefore tends to plug up and cause problems which I have always thought were something else. Rough running engine, loss of power, stopping the engine from running altogether, smoking, corroding, leaking water and exhaust gas are all symptoms of this parts malfunctioning. If you haven't looked at yours, I suggest you do. When it fails, a new one is difficult to find, very difficult to replace and unnecessarily expensive. I have been quoted between $120 and $480 for the part depending on where you fall in the Yanmar marketing scheme and how much the seller thinks that he can stick you for.
A mixing elbow is also called an exhaust riser. It is the inverted "U" shaped fitting on the end of the exhaust system. It has a passage where the raw cooling water is mixed with the exhaust gasses. That is for the purpose of cooling the exhaust before it is passed into the rubber exhaust hose. Mine has been a source of problems since I got this boat. It is poorly designed and therefore tends to plug up and cause problems which I have always thought were something else. Rough running engine, loss of power, stopping the engine from running altogether, smoking, corroding, leaking water and exhaust gas are all symptoms of this parts malfunctioning. If you haven't looked at yours, I suggest you do. When it fails, a new one is difficult to find, very difficult to replace and unnecessarily expensive. I have been quoted between $120 and $480 for the part depending on where you fall in the Yanmar marketing scheme and how much the seller thinks that he can stick you for.
Mixing Elbow is a Casting
I've removed, cleaned and re-installed my mixing elbow on a Yanmar 2GM20F. The inverted "U" is actouly a casting whereby the water inlet nipple goes into a separate cavity on the top of the "U" so it's flow is directed in the downstream direction of the exhaust. It seems to me that if you didn't create this secondary chamber and it's directional flow, you could quite likely flow water the wrong direction into the engine exhaust when you initialy crank it over before she fires up. By the way, it wasn't all that difficult to chip out the major carbon build-up and use a couple different heavy duty wire wheels on a reversible drill to clean out the original casting. In order to get the flanged 90 degree elbow, the vertical riser and the "U" casting apart, I took it to an automotive shop and they did it for $10.00 withut breaking anything.
I've removed, cleaned and re-installed my mixing elbow on a Yanmar 2GM20F. The inverted "U" is actouly a casting whereby the water inlet nipple goes into a separate cavity on the top of the "U" so it's flow is directed in the downstream direction of the exhaust. It seems to me that if you didn't create this secondary chamber and it's directional flow, you could quite likely flow water the wrong direction into the engine exhaust when you initialy crank it over before she fires up. By the way, it wasn't all that difficult to chip out the major carbon build-up and use a couple different heavy duty wire wheels on a reversible drill to clean out the original casting. In order to get the flanged 90 degree elbow, the vertical riser and the "U" casting apart, I took it to an automotive shop and they did it for $10.00 withut breaking anything.
It doesn't have to be a casting
and some other types aren't. My HD MK2 MOD3 does the same thing as the casting if not better. The water is directed to the same general location and has the same effect as in the factory part. The main difference that I see is that the water passage is not an integral part of the system. The water passage in the casting does cool the top of the elbow. The water passage in my design is the 6 inch x 1/2 inch pipe. It is not mechanically or thermally connected to the top of the shell of the assembly and so the outside of the tee does get hotter than the cast part will. My original design was a lot hotter in operation but neither of them is going to allow water back into the engine. I have cleaned these things too and the MK2 MOD3 is a lot easier to remove and inspect inside. I go places where there are no shops to take it to so the fact that I can fix this thing myself is worth a lot to me. Reverse threads be damned - I can get replacement parts just about anywhere. I am surprised that the output side of the manifold is a standard thread. Someone in the Yanmar "You can't do that yourself" department messed up.
and some other types aren't. My HD MK2 MOD3 does the same thing as the casting if not better. The water is directed to the same general location and has the same effect as in the factory part. The main difference that I see is that the water passage is not an integral part of the system. The water passage in the casting does cool the top of the elbow. The water passage in my design is the 6 inch x 1/2 inch pipe. It is not mechanically or thermally connected to the top of the shell of the assembly and so the outside of the tee does get hotter than the cast part will. My original design was a lot hotter in operation but neither of them is going to allow water back into the engine. I have cleaned these things too and the MK2 MOD3 is a lot easier to remove and inspect inside. I go places where there are no shops to take it to so the fact that I can fix this thing myself is worth a lot to me. Reverse threads be damned - I can get replacement parts just about anywhere. I am surprised that the output side of the manifold is a standard thread. Someone in the Yanmar "You can't do that yourself" department messed up.
Patrick, pictures and more pictures
Then post more pictures. Standing by,,,for pictures. Did I mention pic-
Then post more pictures. Standing by,,,for pictures. Did I mention pic-
Problem with Cleaning Mixing Elbow
The problem with cleaning the mixing elbow is this doesn't stop the rusting - it only removes the carbon buildup. One can usually get by with cleaning the mixing elbow about 1x and perhaps 2x if it is done frequently. However, the rust will eat through the sidewall of the elbow and then it's shot. Running the engine at this point isn't recommended. Depending on the frequency of cleaning, if one tries to go 2x then inspect frequently for the breakthrough. Recommend spray painting with a light color VHT spray paint otherwise it can hard to see the beginnings of the crack, and carry a spare with the wrenches to replace in the field. From my experience, cleaning it 1x is just about the economic limit.
The problem with cleaning the mixing elbow is this doesn't stop the rusting - it only removes the carbon buildup. One can usually get by with cleaning the mixing elbow about 1x and perhaps 2x if it is done frequently. However, the rust will eat through the sidewall of the elbow and then it's shot. Running the engine at this point isn't recommended. Depending on the frequency of cleaning, if one tries to go 2x then inspect frequently for the breakthrough. Recommend spray painting with a light color VHT spray paint otherwise it can hard to see the beginnings of the crack, and carry a spare with the wrenches to replace in the field. From my experience, cleaning it 1x is just about the economic limit.
Other Materials
It would seem to me that in this day and age that there is some type of plastic or carbon fiber that can be used to make this elbow from that should last a LOOOONG time. But then the idea of planned obsolesence is what keeps alot of companies going. I am too interested in the Home Depot model. Bob F.
It would seem to me that in this day and age that there is some type of plastic or carbon fiber that can be used to make this elbow from that should last a LOOOONG time. But then the idea of planned obsolesence is what keeps alot of companies going. I am too interested in the Home Depot model. Bob F.
No Teflon tape
I have been advised not to use teflon tape on the exhaust fittings. When they get hot, they produce a dangerous gas which in one instance of use on a military power unit killed some 17 people. I will post a picture soon. I have some other duties first.
I have been advised not to use teflon tape on the exhaust fittings. When they get hot, they produce a dangerous gas which in one instance of use on a military power unit killed some 17 people. I will post a picture soon. I have some other duties first.
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