FIRST OFF.......
You need to clean that sooted rusted disaster up :B
Remove burner tube from gas valve and combustion chamber along with pilot flame tube and thermocouple
Remove exhaust heat shield
Clean burner assembly with wire brush and small bottle brush thru tube
Scrub exhaust shield clean
run a wire thru combustion/exhaust tube, tie rag on wire and pull it back thru several times to get soot/rust out
Reassemble
Loosen screw and move clamp back opening air shutter FULLY
Fire it up
Slowly move clamp closing off air shutter until MAIN flame is strong, steady blue flame with just a tinge of orange at tip. then tighten screw
Should be no more sooting going on
OR you may have to buy new pilot flame/thermocouple/burner tube assembly to make it work
