This was because the ignition system wasn't always receiving a good strong input power at it's low tension side. (mechanics.stackexchange.com)
The company further explains — The patented armatures work together to deliver sizzling highs and can withstand extremely high input power without distortion. (techtree.com)
This core welder comes with a 10» lead MIG gun and 10» ground clamp, gas hose, regulator, and 15» input power cable. (geekwrapped.com)