I got a Tower .75 on an Uproar 60 that I haven't flown.
Here is the problem: The muffler kept rotating around the screw that holds the three pieces together. Since I didn't have any locktite or a matching nut to double nut the thing I put a drop of solder on it to secure it from coming loose.......But the muffler STILL rotates.
Is There a means to permanently weld the pieces together.. I can Arc Weld And Solder , But I dont braise.
How about JB Weld?
1 more thing anybody got a fix to quiet this sucker down. I thought about a Bisson Muffler but I don't want to spend 40 bucks on it unless I have to and I know it will quiet it down. I have a Husqvarna chain saw with a 70 cc
engine and I swear it ( the tower .75) was louder, the muffler worked its way off once before I soldered it and and I almost couldn't tell the difference..
I don't mind loosing a few rpms for some for a few decibals. It needs to lose about 20.(guessing).

Get a MAC muffler.

Mac From where?

Most of us locally use silicon to stabilize the Tower muffler.

The GMS 76 muffler at $16.99 is a direct fit and quite a bit quieter. I've flown it and it works quite well but does cut a little power.

http://www3.towerhobbies.com/cgi-bin...?&I=LXEHA2&P=7

An example of the welded approach to a common problem in this case it was done with heliarc:


John

I have other brands of muffler that also like to come apart. I used JB weld on them and it holds great.

Stripes- thanks I think the GMS muffler looks like the best solution. I knew they fit but didn't bother to look at their stock muffler.
Even if I used JB or got somebody to heliarc the Tower muffler it would still be loud. I live on a farm 5 miles from the nearest town so noise is not a problem there, I just don't like it. I think I will go with 4 strokes on anything larger.

Thanks to everybody.

The GMS and Tower mufflers are exactly the same and have the same "rotating" problem.

However this is easily cured.

Everyone ( including myself ) assumes that the lock nut at the back of the muffler is what is supposed to hold the whole assembly together.

We tighten it down, and then are surprised to find the muffler loosening or rotating in flight.

I've tried JB Weld on the whole thing and merely end up making a mess, as the JB weld will dissolve with the heat and glow fuel...


Instead of all of this, leave the locknut off initially.

The long screw threads into the back end exhaust part of the muffler. This is what you need to get tight and assure that it will not turn.

Remove the cardboard washer from the long screw. Insert the screw and assemble the muffler as usual. Put in Locktite at the screw or receptacle.

Tighten it down carefully and as hard as you can WITHOUT stripping or hurting the screw head.

This will pull the back end towards the front.

Now grab a heat gun or torch and heat up the junctions of the cylinder.

You'll find that the scew is loose again. Tighten it down as much as possible.

Repeat the heat cycle and tightening.

Finally install and tighten the rear lock nut... preferably install a second one against it to prevent them both from turning in flight.

The only time the JB weld let go on my muffler was in a very bad crash. [8D]

I've tried it on various things.

It works like a champ on anything that doesn't build up a lot of heat...

But sooner or later ( and usually sooner ) when I use it on mufflers it turns it a grey chewy mess, that doesn't brighten my teeth!

I've got two Tower .75s with several flights on them, and I haven't had a problem with either muffler coming loose. I always put Tamiya threadlock on the bolt/nut and tighten it up good, never had it come loose or rotate on me. The Tamiya threadlock is gel, unlike the runny Loctite threadlock. I put it on all my muffler bolt/nuts, and I have not had one come loose since.

Yeah, the Tower .75s are a little loud, but they sound great to me, and put out plenty of power. Excellent value for the money.

That looks NOTHING like the muffler that came with my GMS .76.

That looks more like an O.S. muffler.

Here's a pic of what I got.

Notice the double lock nuts at the end.

Had the same problem with the tower 75 muffler.. In fact I'm on my second one now because the first one "departed" the aircraft.. After getting muffler number 2 I tried putting the whole thing together with JBWeld and found it to be no help. I think that JBWeld dries into such a hard substance that it doesn't hold up well to the vibration of a 2 stroke engine.. I Had jb weld flaking out after a few flights.. After that I was determined to stop this problem dead in its tracks.. First I took the entire thing apart and cleaned it well with mineral spirits. Then I put the whole thing back together and used the red high temp RTV Silicone for making gaskets with.. great stuff.. Then I drilled some very small holes in the muffler where the can meets the front and the back housing and put some small screws into these holes to. Lastly, I threw out the through bolt that comes with the muffler and put a piece of threaded rod from the hardware store through the whole assembly and double nutted both ends of the threaded rod.. oh yeah, also used red locktite on the two double nuts... That bad boy hasn't even considered rotating on me or vibrating loose..

http://www.rcuniverse.com/forum/m_54...tm.htm#5706658

Pics above of what I did..

Yes, but. . . that's what used to come with the GMS. Tower does different things over time. That muffler is still available and not all that expensive.

Yes.

I'm afraid however, that if you order one of these you'll end up with the stock GMS muffler.

Even the parts breakout pictures have the other.

I've received several .75 and GMS .76 engines recently and all have had the muffler I pictured.

Great idea... I'm already drilling!

Thank alot everybody,

I had already come up with the idea of a threaded rod but just got to the internet to check out RCU.
I am glad to see someone else already tried it, it looks like the best way to go if I keep the Tower muffler on it.
I can probably put up with the noise once its more than 10 feet from me, as long as I know the mufflers gonna
come back with the plane.

Thanks again.

just tac it on there if you can arc weld. A couple of tac would do

I use nyloc nuts. look in the heli section for correct thread size.
add blue loctite or JB weld. I don't JB weld the muffler, I JB weld the threads and the nut.

You can try putting course steel wool inside to make it acts like a baffle to reduce the noize.

Steel Wool... H'mm might try it..
I might be able to tack the nuts on but if you touched that aluminum it would just blow a hole through it..
I'll just stick with the threaded rod. but thanks for the steel wool idea..kinda like the Cherry Bombs I used to put on my 74 Nova... they would sound great till they burnt out.

you might want to wrap that steel wool in screen wire as I think some of it could wind up back in the cylinder if you don't .

Steel wool is - NOT - a good idea!

It will oxidize in the heat, ( just put a match to steel wool to see what will happen ) resulting in particals that at worst could make their way back into the cylinder head.

Yep your right, I guess I better not put anything inside the muffler that aint bolted in.
I still might order the GMS muffler...If it aint like the seperate one on the tower website and it looks like the one that comes with the .76 I'll just send it back. My GMS .32 has a nice muffler.
I know two strokes are loud but I have had snowmobiles that were real quiet.. more noise came out of the intake then out of the exhaust.

Thanks again