Popping in silencer??

[ClassicBiker]

Not a mixture or air leaks question !!

I've never known why Vins don't use megas, never questioned it, straight pipe always worked well for me on the track.

After trying various silencers on my roadgoing Egli a few years back I finally found a reverse cone mega (style) that let the engine run right and didn't burst my eardrums. The only problem was a funny plopping sound in the exhaust on tickover. After a few months, I took the silencer apart to discover the "mega" had a tube with baffles round it, and the "reverse cone" was just a cone. I put a tube (piece of exhaust) through the cone to the baffle tube and heypresto, plopping sound gone.
Today, I've fitted a new silencer (the old one was getting a bit scruffy) similar style but a bit shorter and the plopping tickover has returned. Looking down the silencer, the baffle tube again stops before the reverse cone.

OK, clever people, WHY??

H

I got a little curious about all this and "googled" "cross sections" and "cut away views" of "reverse cone" and "refraction" mufflers. I got some strange stuff pop up. In the flotsam that floated to the surface was some relevant cut away and cross sections. The majority of which matched your description. So it would appear this is normal practice and an intentional part of the design. Beyond that I couldn't find much.
Steven