I am having trouble getting high temps in my Large BGE. I cleaned all the ash and old lump out and still can't get much higher than 450 after 20 minutes. I want to get the thing up to 750/800. I am using Real Flavor lump. Where should I set the vents. I have tried the daisy wheel in numerous settings with the bottom vent wide open. Do I have pack a ton of lump in it and get it all lit with the mapp? Any ideas are appreciated.