My own thinking: to make good welds, you need to have a good technique
(you already have it), correct voltage at all times, correct feed
speed, and proper gas flow.

So. You already have a good technique and check the remaining
factors.

Get your buddy to help.

1. Have him monitor voltage while welding
2. Have him monitor feed speed by watching the spool turn, to see if
it feeds unevenly.
3. Stick a flowmeter in the gas line to see if the flow is consistent
with what you want it to be.

Somewhere above you will probably find your answer. Check the liner
too.

i