Im installing smoke in a 100cc Yak with a DLE 111. The question I have is about the muffler. Should I run a tube through the muffler in a horse shoe or U shape to prolong the heating of the oil or is this not necessary and just install a fitting close to the cylinder. If the U shaped tube is the way to go would JB Weld be suitable to epoxy the tube in place. The tube would go completely through the muffler long ways and make the U bend and go back into the muffler and dump near the center close to the exh port coming out of the head. If a tube is used does the heat tend to clog the tube over time? I saw this many years ago and never found anything out about it because I wasn't interested in smoke at the time. In theory It looked good, I just don't know if JB will take the heat.

A fitting close to the cylinder should be good enough

This is all you need to do.

Well that certainly takes all the complexity out of that problem. That might take all of ten minutes to drill and tap. I guess I was making this harder than it had to be.

SF,
I ran into the same question and did a little experiment on my DA 150. In one of the muffler downspouts I did the coil/pre heat thing and left the other one open and just tapped the muffler up close to the engine. In flight, after the engine got warmed up, I noticed NO appreciable difference in the amount or quality of the smoke that each side of the muffler produced.

Hope this helps,
paul

Pre heat coils are for glow technology. Glow engines run cold. Gas engines run MUCH hotter, which is where a lot of converts from glow run into trouble.

All you need is an oil injection source close to the exhaust opening for a gas engine to have an effective smoke muffler. Been saying this for years but people keep spending a lot of extra money for glow style smoke mufflers. Slimline has to love newbies to gassers.

Thats why I asked. Thanks for the reply TOM

I appreciate everyones responce. I thinke the fitting in the muffler couldn't be easier.