ignition problems

The only way an engine can idle at high rpm is if it is getting too much air. If your throttle plate is almost closed, i.e. the idle speed screw is in the normal position and the choke is open (speed cam out of the way), then it must be getting air from somewhere else, i.e. a vacuum leak.

Check the common and easy places first. Detach each vacuum hose from the carb and plug the port, one at a time - PCV, brake booster, vacuum advance, charcoal canisters, etc. If it slows way down for any one, you found the leak. Since you say the idle is really high, I would suspect the big hoses (PCV or brake). You could also have a leak at the throttle shaft of the carb. For many hoses, you can hear it hissing. I fixed a relative's Honda Civic once. They said the engine "sounded funny" at idle and was rough. It was idling ~1500 rpm and I could hear the hiss from a 1/4" vacuum hose. Popped it back on and it purred like a kitten.

Some people try flowing propane (not burning) around the intake - head junction and the carburetor base to see if the engine idles smoother (but not slower), in searching for a vacuum leak. I have heard of spraying carburetor cleaner similarly (but not around rubber diaphragms!).