It looks like the welsh plug was pried out with a sharp object and has been replaced. Don't know if it is leaking.
Symptom: saw starts, revs and dies as if it was turned off. Revs for 2-3 seconds only then cuts.
Oddly enough I also have a Husky with similar HDA carb and it is showing the same symptoms.
Getting a hate on for these carbs.
Is the plug dry or wet? If it's wet go after the main nozzle check valve.
I've had several different symptoms on that issue. Tunes OK but goes lean after a couple of seconds at full throttle. Can't be tuned on the high side. Runs best when it's puking fuel. The latest was on a Dolmar which started hard and then idled but cut out shortly after whether I was on the throttle or not.