I am fed up with the muffler on my saito 180 loosening up every other flight! I have tried Industrial strength loctite 554 and Teflon tape but both of these methods have failed. Anyone have success with RTV. Or would it be better to just JB weld the thing in place.

On my Saito 82 I just torqued the nuts up once the engine was hot and it's stayed tight since then.

On my Saito 100 I just used lots of teflon tape and did the same thing (torque it while it's hot) and all's fine.

It helps (I think) if you make sure the header pipe is screwed in far enough to bottom out in the head.

Where is it coming loose head or muffler? I've had good luck using permatex high temp in the gold tube... I used it to seal the threads though... the muffler never loosened before or after using it... I've also used teflon tape good results.

Have you tried tightening the nut's right after you fly it? the heat can help set the nut's better.

I wonder if you have bad threads in the mix? maybe replacing the header pipe would help? how about trying a double nut at one or both ends? how about drilling a small hole and running a screw in it if the problem is at the muffler end?

JB would work but I sure wouldn't use it unless I had no other options.

John

It seems that only the muffler is loosening. I dont know why. The manifold and nuts are staying put though. When you say bottom out do you mean screwing the muffler all the way in?

Yes, screw the nut on as far as you can get it. Then screw the muffler up against the nut lightly. Back the muffler up just enough to get the pressure nipple where you want it. Then tighten the nut against the muffler with a wrench.

Start the engine and run the engine at high speed for about one minute. Shut engine down and retighten the nut immediately while the assembly is real hot.

Enjoy,

Jim