I did a double take when I peeked under the kiln this morning and saw this...
All of the burners were wrapped with foil with a single hole poked through with a pencil.
The explanation was that during candling with the ball valve just cracked at low volume, the gas could actually burn back to the orifice due to the high ox to gas ratio. The flame sitting on the orifice is just asking for complications.
Steve's solution to is to cut back the primary air with the tinfoil... the hole poked through adds a just the flow of air needed to balance out the burn and keep the flame burning above the burner right where you want it.
Just pull off the foil when it's time to really crank'em up.