Why do pods "cough"?

[JimmyR]

Hmmm... Very interesting. I have this happen on my bike too, and I've been fixing/replacing pretty much everything on it. My bike has K+N pods and RS36 Mikunis, and I reckon I've got the jetting almost spot-on now. For me it happens sometimes when just riding along a highway and not changing speed or anything. Or it will happen when idling at lights. I call them carb farts. Really annoying because I have gone to so much trouble to sort out everything!

I will be interested to see if it still happens when I get my bike up and running again - I've just redone the valves and rings mainly because of leaky valve seals. I am really hoping that the coughing/carb farts have gone when I get the bike running again. Like Mr Cinders it is somewhat intermittent and doesn't seem to be caused by anything predictable. For me it doesn't happen because of acceleration or deceleration but happens at constant speeds or idle. It does seem to cause a loss of power for a moment. Annoying.

[Dave8338]

One other thing that can contribute to a backfire / cough on the intake side, are carbon deposites on and around the intake valves. They tend to glow white hot and can easily ignite a rich intake vapor, prior to the ignition cycle. Mr. Cinders... you mention that your bike is running rich, plugs are sooty, ect. It is my thought, that this may indeed be your issue. Also to note: when running pods or a modded intake, your mixture is no longer the same as the stock setting and many times with the "trial and error" tuning it takes to get things right, RICH mixtures are part of the process.

Hope this helps a few.