TQ secondary not opening up all the way

Vac choke? I am assuming you are referring to the dashpot mounted on the pass side, rear of carb. Various names used for it. It plugs into a port in the carb base, the port closest to the dashpot. Some of those ports are a brass tube with a very small hole in the end, about 0.015" diam. Would not take much to block the port.
To test: remove the hose. Push dashpot plunger in with screwdriver tip & let go. It should return fairly quickly from internal spring pressure. If this fails, dashpot is faulty & needs replacing. If OK, connect hose to port & re-test. Plunger should return; if it doesn't the port is blocked.