Yamaha 8hp 2 stroke won't take gas

[anamealreadyinuse]

My Yamaha 8hp 2 stroke 80% of the time won't take gas. She starts up fine on the first pull but when I attempt to throttle up it stalls out. Occasionally she will throttle up but when I come back down to idle and throttle back up she'll stall again. When I can reach full throttle the engine sounds like it's "missing" or stalling but does continue underway when I am able to throttle up. I replaced the spark plugs b/c they were dirty. I adjusted the throttle pin to a few turns counter and clockwise and then adjusted it 2 turns counter- clockwise from fully closed to try and dislodge any junk. A month ago, I also had the carburetor blown out by a marine shop because it would stall out when idle so I believe the carb is clear. The only other thing is that about 9 months ago the carburetor was acting up (stalling at idle) and my father in-law took it off and said he noticed the "throttle plate?" (little dish/wafer) within the carburetor was really tight and they tried to loosen it up. He is wondering if they damaged it...does any of this ring a bell or can you guys point me in a direction of where to look?