An engine with an overly lumpy idle means that the engine builder didn't do his homework right. The ideal engine would start easily, idle smoothly, and pull strong from idle to top RPM without any noticeable flat spots or loss of torque. Since that's not usually possible, pick an upper and lower RPM figure that you want to stay within, and engineer things to perform within that range. If you just want to have one that shakes the fenders and sounds like it's doing something, pull a couple of plug wires.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!