JPMacG

My Feedback: (2)

I have an old Soundmaster muffler on my Enya 50SS. It is great, sound level is very good and power is not reduced. In fact, the engine seems more powerful with the Soundmaster than with the original Enya muffler.

The soundmaster is made from thinwall steel that is brazed or welded together. The pressure nipple was originally just threaded onto the thin steel, but that lasted about four flights before the theads vibrated loose. So I soldered the nipple on. That worked for awhile, but apparently the muffler gets above the melting temperature of solder, and now that has come apart.

I'm wondering if I can braze the brass nipple onto the steel muffler body. I've done some steel-to-steel brazing before using a small oxy acetelene torch. Can I braze brass to steel? What filler metal should I use?

Thanks

Ernie Misner

I think you could braze it in (good thinking) but it might be too easy to melt the brass nipple in the process. Wouldn't hurt to give it a try. It doesn't seem likely that the muffler got so hot as to melt the solder though. The problem could be that once a muffler is used, it is very difficult to get all of the castor oil out of the pores on the metal. Try heating it with a torch and then use a wire wheel to clean it down to some bare metal. You could try some silver solder which has a higher melting point, or even JBWeld as an experiment. Getting back to the brazing, you could simply braze in a tiny steel tube and be good to go. You will get this solved.

Ernie Misner

SrTelemaster150

High temperature silver soldering might be your best bet. Even if the soft low temp solder doesn't neccessarily melt from the muffler heat, it is weakened by heat.

Although the brass will start to glow red, the hi-temp silver solder melts below the melting temperature of brass. It's what is used to solder copper tubing in refrigeration systems.

For your application you need a very fine (torch) tip.

You could also weld a spot of steel to the muffler body to add some thickness, dress it down flat & tap it for threads.

earlwb

Yes the high temperature silver solder is a good approach. You might be able to get a tuned pipe thin wall fitting in there too. You have to use a l;ength of wire and sort of pull the fitting in from the inside out and then put on the nut.

I have a fitting on one of my DDD mufflers but honestly, I have totally forgotten about what I did to get it installed like that. Or whether it came from DDD already installed too. But it hasn't come loose on it yet. Or if it was a thinwall fitting or not.

Sport_Pilot

I see that is a Fox engine. But I don't think Ihave seen that particular carb on a Fox before.

earlwb

That is arguably Duke Fox's best carb (at least until Fox put out their current carb) of the ages. A three needle Fox carb. We have a low speed, mid range and high speed needle, albeit we don't need the idle speed screw much anymore. But just think of it, you could adjust the engine for low, mid and high speed running. That sort of makes it the ultimate carb to use. When Fox first put out the .74 and later the .60 engine the three needle carb was sort of the descerning pattern flyer carb to use, not really a beginner carb for users.

That carb was replaced with the Fox butterfly valve carb later though, which was replaced with the MK-X carb and then the EZ carb and finally we have the current carb that Fox produces.

JPMacG

My Feedback: (2)

I was able to get the end cap off, so now I'm thinking I'll just get a new nipple and put a nut on the inside.

The muffler in the photo appears to be exactly the muffler I have. I also have a Fox 74 and wish I could find a 70 sized Soundmaster to fit it. I was lucky to find the 50 sized Soundmaster on flea bay, but the larger version seems to be very rare.

Ernie Misner

How do you decide which plug to put the igniter on?

earlwb

JPMacG, I would use the tuned pipe fitting or thinwall tubing fitting, it is easy to install from the inside and the nut goes on the outside. Just use a length of wire to thread it through and pull it up so you can slip the nut on and tighten it down. Yeah that is the larger muffler. I have had it for many years now too.

Ernie Misner, it doesn't matter which glow plug you use to start the engine with. The other plug will heat up from combustion and work automatically.

SrTelemaster150

Double post deleted.

JPMacG

My Feedback: (2)

Thanks Earlwb. Who makes the tuned pipe fitting? The only fitting I can find at my LHS is one by Dubro with the nut on the inside.

earlwb

Mac's makes them for their tuned pipes http://www.macspro.com/accessories.asp
here is one http://www3.towerhobbies.com/cgi-bin...&I=LXBWL5&P=ML
I think someone else makes them under their brand name too.
Of course with the nut on the inside of the muffler if it ever came loose, it would be doubtful that you'd lose it. So if it works go for it.