He can't be referring to me. So far my Bullet hasn't kicked back.
It hasn't even backfired since that unfortunate incident which took out the starter gears a few months back.
But generally, lean idle mixture +/- overadvanced timing does lead to backfire - not to kickback in the Bullet, no, not with proper technique and good mechanical condition.
I first find the maximum resistance with the kicker (compression stroke), then I pull the decompressor and then I listen for the noise in the exhaust. Once I'm sure the chamber is empty (beginning of power stroke), I let the kicker come up all the way and presto....
It's an entirely different issue regarding that backfiring thing. Kickback occurs only with the kicker still engaged and crank rotation reversing because of lack of momentum to get through TDC before the burn starts seriously (that's why lean and advanced aggravate the problem). That really isn't supposed to happen with a properly executed kick start attempt because the kicker will be disengaged by then.
The bigger problem from a design perspective is instantaneous reversal of rotation somewhat later during starting or even at idle. That problem (call it backfire if you will) takes out the starter gears. And you don't have to use the ES for it to happen. Doesn't happen much in a perfectly tuned Bullet apparently. Good example of what happens if you just repair the damaged starter gears is found somewhere else here:
http://www.enfieldmotorcycles.com/forum/index.php/topic,248.0.htmlIn any case, just a vulnerability of the ES cycles, although it can't be good for the worm drive....
Peter