Popping from exhaust at idle

What causes popping from the exhaust at idle?

I noticed last night that while my bike is sitting idling, it pops intermittently from the right side exhaust. Left side pipe does not do it.

Most likely culprits:

1) fuel level wrong in the right hand side carburetor

2) pilot mix screw not adjusted correctly

3) pilot jet dirty

Another suggestion would be to check the valve clearances as a "tight" valve may not be seating properly.

Popping can be not only mechanical (valves not adjusted), but can be from air leaks at the intake side, bad exhaust crush gaskets or can be incomplete combustion due to poor spark or mis-adjusted timing.

All others, plus this, popping is usually a result of unburned exhaust igniting in pipe.probable cheap causes are lean mixture, intermittant/weak spark. one that beat me up was a burned valve & seat. valves walk around wilst running and when pitts lined up,compression dropped low enough that burn was incomplete resulting in incompete burn charge exiting ex. port to be ignited by following heat. I'd try a set of points 1st and a EGA, since the only way to chk this is visual. luck g