Okay, now we have something to go on-
First, you need to measure the fuel height in your carbs by the Clear Tube method (attached).
Then, 4 fresh plugs once you extract the stuck #2.
Are you operating the Choke properly? Many reverse its settings by misunderstanding the lever.
I mean no disrespect to the PO or his Mechanic, but do NOT rely on their statements. You must perform a comprehensive tune up per the manual, the 3,000 Mile Service Interval is the best place to start. Once you have done these, then, and only then, would I worry about it not running properly. After YOU HAVE CONFIRMED the settings and state of tune. Anything short of this is foolhardy and a waste of time, says numerous experienced buyers of vintage motorcycles.