Muffler/Expansion Chamber - Making One

[loquin]

First, I want to report that the silicone "muffler" tubing from Daves Motors does NOT hold up to the heat from my Mitsubishi TLE43. Possibly it would work OK on a 4-stroke, as the exhaust isn't coming on every engine revolution. It begins to break down, and eventually, it will fail. That's not to say you can't use it, but you'll need to replace the portions close to the engine every hundred miles or so... This means that I'm fabbing a muffler outlet port adapter next.

In addition, I've ordered fiberglass "roving" cloth from fiberglasssite.com
With the design I have, I can switch the end caps to a new, longer silencer body when I do the next round of testing. That way, I can see if there's a major impact of increasing the length by another 4-6 inches.

OK. Here's a few pictures of the Swiss Silencer assembly.

• The first photo is the 1.5 inch coupling, cut in half, with the 1.25 inch hole plug drilled and inserted into the half-coupling.
• The next photo is of the inlet end cap, assembled & brazed. Note that the inlet exhaust tube extends beyond the end cap.
• The next photo is the dry-fit of the silencer shell assembly, showing the two end caps, and the silencer main tube (1.5 x 12 inch conduit.) Note that the outflow exhaust tube isn't completely welded to the end cap.

 

[kerf]

I've been running the silicone tubing on my R460 for six months with no problems. I have found, however, it is sensitive to over tightening of the clamps.

 

[loquin]

When I was hooking up the new silencer temporarily, it just fell apart on mine - about a half inch from the clamp. When I looked inside the tubing at the shredded end, it was charred in appearance, and a bit crumbly. At the other end of the (original) three-inch tube though, it still seemed to be in good shape.

 

[kerf]

Are you connecting to the original muffler or an exhaust flange directly off the exhaust port?

 

[loquin]

I'm connecting to the original muffler.

 

[kerf]

The R460 runs at 25 to 1 oil mix and I may be a tad on the rich side on carb settings, may keep me a little cooler than you. My first attempt at hanging a muffler on my TLE43, left me with solder splattered all over the bike. Maybe the Mits just gets hotter.