krashkart

My Feedback: (5)

I know i have seen it here somewhere but I cannot find it now.
I used plumber's white tape to break in my Saito 82 and it seemed OK.
But somewhere on here I saw recommendations for either loctite or permatex sealant and what type to use on the Sarto mufflers to keep them from working loose.
I do have some on hand. It's loctite thread locker Blue #242 and it says its removable. Can I use it?
What are you using?

billd76

My Feedback: (3)

Blue loctite works well. Do not use any red loctite. They will never back with red, but you'll never get them out when you want too either. Blue will work and you can get the screws out when you need too. It only takes a little for it to work. I also use Hylomar Sealant over the muffler gasket. It's blue and it never hardens, seals great and it's easy to remove. I use it for the vehicles, lawn mowers and motorcycles too.

TimBle

Bostik Super Gasket High temp silicone sealant.

works brilliantly



not sure if you have Bostik in your neck of the woods but any high temp metals compatible silicone sealant will work.

ChuckW

The hight temperature RTV silicone works good. It is generally orange in color and you can get it at most auto parts stores. It can be some messy, ugly stuff though so I would use it sparingly.

I've had mixed success with blue Loktite on exhaust systems. It is a great product and I use it religiously on airplanes but it is designed to soften with heat so it doesn't always work well on some muffler applications.

Villa

Hi krashkart
Use the blue Loctite on the threads, including the muffler mounting bolts. Use Permatex Automotive Adhesive Sealant, available at AutoZone automotive stores, on the flanged surface and on any part of the muffler that comes apart. At the first sign of a leak or any movement, do the whole thing over again. You will never have a muffler problem again. Simple. I know people that lose 3-4 mufflers every year, year after year, after year. They have all kinds of excuses, but never do the suggested things. They also have many dead engines. I seem to go well over a year between dead engines. I wish they would wonder why. Good Luck.

mclina

He is asking about a four stroke muffler, which doesn't have bolts or flanges, it is just a threaded tube with a lock nut. They also run a bit hotter than two stroke exhausts.

I don't remember what I used on my Saito, but I believe it was blue locktite. I checked all of the thread sealers at the store, and picked the one with the highest temperature rating that was not permanent.

Good luck

Villa

Thanks mclina , I missed that. I have never had a 4-cycle, but have seen many problems with loose mufflers on them.

MTK

Permatex Ultra Copper sealant. It is rtv high temp silicone type sealant that (has some gasoline resistance too) works exceedingly well as gasket and/or thread locker. I use it on small gassers too to hold the mufflers or headers on. Gasoline exhaust temp is similar to that of 4 strokes or just a bit hotter. No problems in 100s of flights

krashkart

My Feedback: (5)

OK, thanks, you are refreshing my memory. At work before I retired many years ago we used a red they had it it was bad to ever have to remove but required in some applications.
I have the blue, so I will try it.
Although I must say for break in I cut a strip of plumber's Teflon tape in half and applied it and it did not come lose a bit.
But over time?
And when I removed it I looked to see if the Teflon tape had any signs of heat damage and I thought it looked good.
It's not quite as easy to use as loctite but almost when you have used as much of that tape over the years as I have.

MetallicaJunkie

i use plumber's Teflon tape on my saito 150.... loctite never seemed to work... for some reason that the only 4 stroke i have ever had muffler issues with

if yur gonna use loctite try to clean off as much oil as possible from the threads with acetone

ChuckW

Another trick is to re-torque the jam nuts on the pipe when the engine is hot. A lot of times nothing else is needed.

FLAPHappy

My Feedback: (209)

I agree with MTK's opinion. Permatex Ultra Copper Sealant is great stuff. I was constantly retighening muffler nuts, but I bought that stuff, never had a problem since. It is a Hi Temp gasket sealant, I put on the threads of the manifold tube, then lightly coat the nut and screw them down tight. It dries overnight, and it withstands the hi temps. I bought it at a NAPA auto parts store. Good stuff!

Villa

I find it interesting that Teflon tape has worked for some people in this application. I would never have used it. I have used Teflon tape for many years in industrial piping applications because it was a great sealant and can take high temperatures. However, the reason I would not have used it is because Teflon is also a self lubricated material: it has applications as none lubricated bearings. I always thought the muffler needed not just a sealant, but also something that would keep parts from moving, like Loctite. If Teflon tape works then by all means use it.

Campgems

I've got to third or fourth the High Temperature RTV.

I am really opposed to any locktite on an engine. Yes, it will hold the bolt. It will be more difficult to remove the bolt at a later day. Once you remove the bolt, there is a large amount of residual left in both the male and female threads. This can lead to cross threading as it is difficult to tell if the screw is started straight. Ditto using a tap to clean the threads. The High Temp RTV doesn't pose this problem.

I fly almost all four strokes, so the loose muffler is always something to worry about. I've yet to see one come loose that had the High Temp RTV used. As pointed out above, it doesn't take much. Use it like pipe thread compound. One other thing is to use proper fitting wrenches, no vise grips or channel lock pilers.

Don