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Rotax exhaust studs - use anti-seize or not?

sblack

Well Known Member
I was asked by a guy in my hangar who has a 912 if he should put anti-seize on exhaust studs. I told him I thought he should. Then my spider sense started tingling and I started to wonder if that could make the whole stud and nut turn out under vibration. Perhaps I should have just said the 3 words that men find so hard to say: "I don't know". There is apparently nothing in the Rotax manual. What do people do on lycomings? Any rotax guru's out there that can comment? If he loses a stud in flight and things get burned up I think he will be upset with me, and probably for good reason.
 
https://www.leadingedgeairfoils.com...-914-series-parts/912-914-exhaust-system.html

Not called out, note there is a threadlock on the manifold side of the stud and antiseize at the muffler callouts.

https://www.leadingedgeairfoils.com...25d08d6e5fb8d27136e95/9/1/912-914_exhaust.jpg
912-914_exhaust.jpg
 
Thank you so much. we will redo that installation properly now. I am less clueless than I was when I got up this morning!
 
Glad to help, but I'm just a former Kitfox owner that had a 912 and knew studs don't typically get antiseize on installation and exhaust nuts also were dry.

Mx manuals and experienced mechs are good.

I simply googled and Leading edge had a nice schematic with parts lists.

What cuts the erroneous antiseize when you clean it before installing with the Loctite?

http://henkeladhesivesna.com/blog/anti-seize-in-auto-maintenance/
 
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Glad to help, but I'm just a former Kitfox owner that had a 912 and knew studs don't typically get antiseize on installation and exhaust nuts also were dry.

Mx manuals and experienced mechs are good.

I simply googled and Leading edge had a nice schematic with parts lists.

What cuts the erroneous antiseize when you clean it before installing with the Loctite?

http://henkeladhesivesna.com/blog/anti-seize-in-auto-maintenance/

The nuts don't get installed with Loctite.
The Loctite is for Locking the studs into the cylinder head.
 
I read that he was installing a stud into a head, which has a callout, not putting on an exhaust nut, which is done dry.

He was worried about a stud backing out.

In either case I suggest considering cleanup methods of errant antisieze.

The antiseize goes on the muffler at the callout.

Should have just posted the picture.
 
I read that he was installing a stud into a head, which has a callout, not putting on an exhaust nut, which is done dry.

He was worried about a stud backing out.

In either case I suggest considering cleanup methods of errant antisieze.

The antiseize goes on the muffler at the callout.

Should have just posted the picture.

My error, I thought the question was about antiseize for the nuts......
 
Scott, I imagine that you are correct in the actual situation, but I may have mistaken word-parsing the OP. Either way, the only anti-seize appears to go at the muffler ball joint. The only loctite IF installing a new stud in the head, I misused the word "manifold".

I never had to set a stud on my 912. Exhaust was easy to R&R and matched the LEAF diagram.

I think the .jpg probably covered it, short of torque specs and any spring retention/preservation twists of safety wire and beads of RTV. If that is even a best practice anymore on the 4 stroke Rotaxs.
 
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