its jus co2 pub gas i think
It might be the gas. Even 10l/min is high for a wee set like that. If your welds are covered with a brown sooty residue, it's a gas problem - wrong gas, or too little/ bad flow.
However it's far more likely you have your wire speed set incorrectly. Have a mess with the adjustment, listen for the smooth sound of frying bacon.
Good luck