Exhaust elbow yanmar

[Jacana]

What is the best way to separate the elbow,manifold joiner.Thanks and Merry Xmas.

[skipperpete]

A fair bit of heat, a good solid vice and a big pipe wrench..... or maybe 2 pipe wrenches. I have a vague memory of that pipe nipple being a left hand thread on one side and right hand on the other .... like a rigging screw.

[mcpusc]

when i brought mine to a shop and had them change it out, they put it in a vise and used a BIG pipe wrench with a cheater bar to break it loose.



the nipple is left/right threaded, examine carefully to make sure you're loosening in the correct direction!

[Wotname]

The manifold side of the nipple is a normal RH thread, the mixing elbow side is a LH thread (IIRC).

Skipperpete recommends a 'a fair bit' of heat. I recommend double that and heat cycle it a few times with shock cooling.

[malbert73]

When I replaced mine on my prior engine (4JHE) I gave up and bought a whole new assembly

[Island Time O25]

When replacing mine, on the first try, I have bent the handle of cheap Kobalt wrench. After going up several wrench sizes (not Kobalt) it finally turned. Still keeping the bent wrench as a reminder to use the right tools the first time.

[chris mac]

When I got my boat, the exhaust elbow needed to be changed. I took it apart to the same stage you have there. (Although mine was a lot more corroded)
The yard manager helped me out with a vice and 48" pipe wrench. It still wouldn't budge!
We used a grinder to cut it through and the threads were fused together. Essentially welded from corrosion and heat.
So I guess I'm suggesting a vice and big wrench, but be aware both sides may be needing replacement.
I hope you have better success than I did!

[Kello]

malbert73 probably has the best solution. Some years ago I had a new mixing elbow with the 2-way threaded SS gas fitting already attached, The engine actually needed a riser and I couldn't remove the short 2-way fitting myself so I took it to a shop. They had a massive table and vise, and the biggest wrench I have ever seen, and couldn't unscrew it ... not even with a four-foot cheater bar on the wrench handle. Impressive! Shoulda used more heat.


But, you likely are having difficulty unscrewing the SS gas fitting from the exhaust manifold fitting - yes? As others have said, it is 2-way, the threads go two different directions, R and L, be sure you are forcing the correct direction.


If that fails, looks like a Yanmar, and looks worn: order a new exhaust manifold fitting, if you have to wait for it to arrive from Japan then work on something else in the meantime. The 2-way threaded SS fitting can be (not easily) found from high pressure gas supply outfits. I've seen that mixing elbow on ebay.


Let us know how it goes.

[hpeer]

Buy a new one here. $ are right. Cheaper than even your labor.

https://hdimarine.net/product/gm-sta...-mixing-elbow/