If you can find an emmissions compliance sticker under the hood, what does it say?? For example...
Idle speed = ???rpm
Idle mixture; adjust to achieve XX% CO in the exhaust.

Spark timing:
maybe it'll tell you to disconnect some hose, plug some hose or whatever...

You used to be able to buy carb rebuilt kits with gaskets, seals, jets, & accelerator pump plunger. That is... IF it acts bad. Probably you can clean the outside linkages with spray carb cleaner. But you'll want a manual before you screw with the mixture adjustments.

Ignition points... those were fun. You have to use a dwell-angle meter.