Running pulse mig with 3/64 4043 Aluminum wire, on millermatic 350p with push-pull gun to weld a metal thickness of 1/4". Argon is set to just under 40 cfm. Wire feed is 350 or so and i believe its running at just under 23 volts. The push-pull gun selction is on EDGE, for the gun i have. All settings, ARC length and ARC control, are set to factory defaults. As i am new to this and have not had much time to play around with the settings, also not sure which settings to adjust to fix my problem. The problem i am having is constant burn-backs at the start of the weld. Once i get welding i dont think it has maybe happened only once mid-weld. Its just starting out that i have the problems. I have spent much time cleaning the workpiece with a Stainless steel wire brush, which does give me a better weld but does not help at all with the burn-back issue i am having. I was considering playing with the Hot Start setting or the Pre-flow setting, but again i am new and im not sure if this will help. I am going through tips alot faster than id like, 5-9 in an hour workday and i dont spend nearly the whole day welding. I have tried to do some research on the internet without finding much helpful information so if anyone who has experience running this machine/ wiresize combo has any tips it would be greatly appreciated, thank you very much in advance.