If it runs better as you richen the idle mix and it ran fine before it means, something has made the engine run lean at idle. This could be dirt in the carb or possibly a vacuum leak, leaks can become worse as a engine warms. Even a weak fuel pump that lowers the float level. The only way to be sure about debris in the carb is to remove the top and inspect it ( you may find the bowls clean and still have a blockage in the passages, overhaul time). spraying carb cleaner around the gaskets and fittings on the intake and listening for a change in the way the engine runs can often find a intake leak. You car also richen the idle even more and see how it runs.