Caution: Do not adjust idle speed on a very hot engine.
Connect the devices for measuring the speed and CO content in accordance with their operating instructions.
Check the ignition timing.
Check the tightness of the intake system. To do this, use a brush to cover all the joints of the intake device on the working engine with gasoline. If the speed increases, this means that the engine is sucking in an increased amount of air in the place just wiped. Localize and eliminate leaks.
Warning: Do not inhale fuel vapors - poison! Do not allow gasoline to splash onto hot parts or the ignition system. Fire hazard!
Check the air filter element.
Turn off all electrical consumers.
Disconnect the crankcase ventilation hose from the cylinder head cover and route it so that it can only suck in outside air.
Check the engine idle speed. Adjust if there is any deviation.
Remove the protective plug (4) through the gap in the upper part of the air filter. If you do not have a special tool, pierce the plastic cap, screw in a screw or self-tapping screw and pull out the screw together with the seal. Press the adjusting device (2) down with a small screwdriver and turn it slightly until the hexagonal end (3) comes into contact with the CO adjustment bolt (61) and adjust the CO content.
Remove the screwdriver from the adjusting device and lightly press the gas pedal, then check the CO content.
If necessary, readjust.
Install the protective plug-seal in place.
Apply partial load to the engine by turning on all electrical consumers (air conditioning, headlights, radio, etc.). The engine should run smoothly, if this does not happen, then adjust the idle speed.
Turn off the measuring instruments.
Connect the engine crankcase ventilation hose.