problem with big 40

[bfdast]

I have a big 40 unknown yr(unsure how to find out) it starts and runs fine idles up when switched. Problem is when welding once you strike the arc it isles up and runs fine, if you lose the arc and get back into it before it idles down it will start jumping and running like crap! If you get out the arc wait till it idles down then start again it's fine! What can I do to search for this problem?? I was a Lincoln guy and bout this machine for 400 and really like it alot, use it more now but really need to figure this problem out

[Tryagn5]

gas or diesel...likely gas...

I have a big 40 unknown yr(unsure how to find out) it starts and runs fine idles up when switched. Problem is when welding once you strike the arc it isles up and runs fine, if you lose the arc and get back into it before it idles down it will start jumping and running like crap! If you get out the arc wait till it idles down then start again it's fine! What can I do to search for this problem?? I was a Lincoln guy and bout this machine for 400 and really like it alot, use it more now but really need to figure this problem out

If it is gas i would bet the governor is acting up, will need to check the linkage to be sure its free, and be sure the governor is working correctly. Also i assume you have an otherwise good running engine...ie serviced.
Kevin