Cheers for the positive comments folks
Alas Radman I cannot really be sure what your solution is
What springs to mind is that maybe when you cleaned out the jet the pinhole has become enlarged and now the flame/heat is too great for efficient heat transfer......
Then again as I said "The symptom was originally fridge alight but failing to chill..." which could mean you are now experiencing my initial problem ...Not getting enough gas
Did you physically take the jet out?
Could there be more dirt in the jet?
Something I did not mention in the post was the supply pipe from control valve to jet.. this can be easily removed, upended and blown through to ensure its clear
A few pics of control valve....
If all is well with the burner end there may be more opportunities for restrictions to the flow in the control valve
