Maybe your bowl needs work. Take a 5 gal. bucket of wter and dump down bowl if it flushes okay the do this. Make sure water level in tank is up to mark, make sure 1/4″ tube is in 1′ overflow pipe. Make sure flapper is working , in your flushing rim on the bowl take a mirrow and look and see if holes are clean, if not take coat hanger and use it to clean out holes. Make sure hole in bottom of bowl is clean, after you do all ofthis and it still does not flush call a Plumber. If your other fix work and drain then your line is not stopped up because the all drain into same pipe.