We are running a XMT 304 CC/CV to weld our wheels. The weld is about 20" long. Recently we have run into a problem with our tips on the one welder getting tight and the wire either gets stuck or slows to a crawl. Our original settings were as follows 27.3V and 600 wire speed, tip was about 3/4" away from the part. That was getting a little hot on the 1/8" material so I changed it to 21.5V, 430 wire speed and tip is about 1/2" away. Originally we thought that dirt was tight in the liner and changed it, matter a fact I even changed the entire cable hose gun assembly. I tried tightening the feed rollers but then the wire gets kinked. Also we are running wire out of a drum and getting below the half way point so I tried putting on a fresh spool of wire but no change. Any ideas would be great.