Ford Carburetor Idle Speed Adjustment
1 – throttle stop screw for adjusting engine speed,
2 – mixture composition adjustment screw
1. Warm up the engine to normal operating temperature.
2. Connect the exhaust gas analyzer and tachometer.
3. Hold the engine speed at 3000 rpm for about 30 seconds, then release the accelerator pedal (or the throttle valve in the carburetor).
4. Wait until the analyzer readings are established and read the CO concentration readings in the exhaust gases at engine idle.
5. If necessary, adjust the engine speed using the throttle stop screw, which serves to adjust the idle speed.
6. If the CO concentration is low, use a thin screwdriver to remove the cover of the mixture adjustment screw and adjust the position of this screw accordingly.
5. Set the engine speed to 3000 rpm and after approximately 30 seconds switch (as in the previous case) to idle speed and check the engine speed and CO content.
8. Install the mixture adjustment screw cover.