The only burners I've made have been with electric squirrel cage fans so I'm not familiar with that one, but I've noticed that brick or castable refractory takes a lot longer to get up to operating temp than kaowool blanket with a thin coating of satanite. Wonder it just needs to heat up a while to get running good?
I have an old high pressure regulator I haven't used in years that you can have if you want to try it. I'm out of town with work this weekend but should be back Monday. I live in Bastrop.