Butane burner help please

[thejesmonddingo]

I've got a 7.5kW burner and stainless boiler,from Rob at the Malt Miller,I'm using it with a 13kg Butane cylinder and a low pressure butane regulator,I'm just doing my first brew,and the flame is really sooty,my boiler is turning black as I watch.I phoned the Malt Miller,but Rob is out until Monday,and I want to do another brew tomorrow,but don't want to wreck the boiler.Am I missing something,is there more adjustability than the the gas control?
Ian

 

[desmosteve]

Take a look at the steel sleeve near the gas inlet, slide it along to get more air in to mix with the gas / nice blue flame! Usually about 75% open or til it goes blue and stable

 

[thejesmonddingo]

Ahh,thank you,knew I was missing something.
Ian