Vacuum Piston

Fig. 4 Vacuum piston adjustment:

1. Adjust vacuum piston gap as described under ``Vacuum Piston Gap''.
2. Rotate curb idle speed adjusting screw in the counterclockwise direction until throttle valve are seated in throttle bore, noting the number of turn required.
3. Fully depress vacuum piston, while holding moderate pressure on rod lifter tab and tighten rod lifter lock screw, Fig. 4.
4. Release piston and rod lifter, then adjust accelerator pump as described under ``Accelerator Pump''.
5. Back out curb idle adjusting screw the number of turns noted in step 2.