I know what you mean about the diffuser (if I'm correct in thinking it's the same part). I was told Butane doesn't burn very clean. I stuck a small wire in there and after about 2 hours managed to get it clean enough that the gas would start flowing again. I've cleaned it more often lately and it's working well. It's a black sticky gunk that comes out of it. The thing is actual about 20 years old now. The little honeycomb catalyst has broken and I've replaced 3 tips over it's lifetime but all in all I am super happy with it since I've cleaned the diffuser.