IDLE SPEED & MIXTURE

1. Run the engine and allow it to reach normal operating temperature.
2. Stop the engine and connect a tachometer in accordance with the manufacturer's instructions.
3. Then, do one of the following:
   1. On ff–1 and 1300G models which have air injection (air pump), disconnect the air hoses from the air distribution manifolds. Plug the hoses and the manifold openings.
   2. On other models, disconnect and plug the hose that runs to the distributor vacuum retard unit, if equipped.
   3. Models that have a secondary air cleaner, or purge valve and hose: Remove and plug the hose that connects to the engine.
4. Remove the air cleaner by disconnecting the emission control system hoses from it, unfastening the wing nut(s), and removing the screws which secure it to its mounting brackets.
5. Check proper idle speed in Tune-Up Specifications chart and adjust to that setting by turning the throttle adjusting screw.

   NOTE: On late model California cars the mixture screws may be capped. If this is the case there is no adjustment necessary.

6. Continue adjusting the idle, this time by means of the throttle adjusting screw and the idle mixture adjusting screw, until a reading of 50 rpm above the proper idle setting is attained.

   NOTE: The idle mixture adjusting screw should have a plastic limiter cap on it. All adjustments must be made within the range of this cap or exhaust emissions will be increased. Do not remove the cap.

7. Then, turn the idle mixture adjusting screw clockwise until the idle speed drops to the figure given in the Tune-Up Specifications chart.

   NOTE: Following this procedure should keep the carbon monoxide (CO) emission level within pollution law standards. However, it is a good idea to have the CO level checked by a qualified technician with an exhaust analyzer whenever a tune-up is performed.

8. Disconnect the tachometer. Reconnect any hoses that were removed. Install the air cleaner.