- Adjust the idle mixture screws.
- Check the idle mixture screws for damage. Any grooves or bending in the tip indicates a replacement is necessary.
- Look for loose or damaged idle tubes.
- Clogged or restricted idle circuit passages, or air bleeds.
- Carbon deposits in throttle bore – rebuild carburetor.
- Idle rough only when hot. – Check vent tubes to be sure they are not clogged.