[Speedslug]

I always run my oxycon at almost fully open.

I let it run for almost 3 minutes before lighting my torch and then I turn off the oxygen at the torch for the 10 or 15 seconds it takes me to get the natural gas burning.

If I run longer than 15 or 20 seconds the oxycon will start beeping at me although I have never had it shut itself off even if it takes me 3 minutes to get the gas burning.

Starting the oxycon with low 1.5 liters per minute output means that the machine will take longer to push the "stale air" (from sitting turned off over night ) out of the tubes and inner mechanics to get the "fresh" oxygen flowing to the torch face.



The symptoms you are describing sound like "stale air" in the hose lines that doesn't have the higher concentration of oxygen you want and that is why the flame flutters and fluctuates on you.