Vacuum Piston Gap Adjustment

Fig. 3 Vacuum piston gap adjustment:

1. Remove air horn cover.
2. Measure vacuum piston gap, Fig. 3.
3. If necessary, adjust by turning adjusting screw. Turn adjusting screw in clockwise direction to enrich the air/fuel mixture. Turn adjusting screw counterclockwise to lean the air/fuel mixture.
4. After completing adjustment, reinstall air horn cover.