Rough Idle or stall
This can be caused by several things, but there is one item often missed by the rebuilder and that is the idle tube. These are very small passages and get clogged easily with ethanol residue. Use thin wire to clean out the passages completely. Blow out with compressed air. A whistle with air will indicate a clean passage. If wire doesn’t do it, try heating the outside of the passage and then blow air through. There may be a small air restrictor in the passage that makes getting through with wire difficult.