Air/Fuel Mixture: Adjustments

Lean Idle Adjust:

Refer to ``Carburetor'' to remove plug covering mixture adjusting screw as described under ``Concealment Plug Removal.''
1. Connect suitable tachometer as outlined under ``Idle Speed, Adjust.''
2. Start engine and run until it reaches normal operating temperature.
3. With engine running at idle, observe fuel level through float bowl sight glass. If fuel level is incorrect, check and adjust float as outlined in ``Carburetor.''
4. Turn ignition switch to off position and prepare for adjustment as follows:
a. Remove plastic limiter caps from idle speed and mixture adjusting screws, if equipped, using suitable pliers.
b. Install air cleaner, if removed and ensure that vacuum hoses are properly connected.
c. Start engine, turn off all electrical accessories and place transmission selector in neutral.
5. Adjust idle mixture by turning adjustment screw inward or outward as needed to obtain highest possible idle speed.
6. Adjust idle speed to specified lean drop adjustment RPM, Fig. 3, with throttle stop (idle speed) screw. Ensure that electric engine cooling fan does not run when performing adjustments.
7. Repeat steps 5 and 6 until idle speed cannot be increased by adjusting mixture screw.
8. With idle speed stabilized at specified lean drop adjustment RPM, turn mixture screw in (clockwise) slowly to obtain specified RPM drop, Fig. 3.
9. Stop engine and install replacement limiter caps, concealment plugs.
10. Road test vehicle.