Warm up and turn off the engine. The oil temperature should be at least 60°.
Turn off electrical consumers.
Check the condition of the air filter insert (see section "Removal and installation the air filter").
Connect the devices for measuring the number of revolutions and CO content in accordance with their operating instructions; the air filter remains removed.
Disconnect the crankcase ventilation hose.
Start the engine at idle speed.
Check the tightness of the intake system. To do this, use a brush to cover all the joints of the intake device with gasoline. If you briefly increase the engine speed, air will be sucked in at 8 loose places. Localize and eliminate the 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 engine idle speed. For the specified value, see the table in the "Ignition System" section.
In case of deviations, find and eliminate the malfunction according to the malfunction diagnostics table.
Check the CO content. For the specified value, see the table in the section "Ignition system".
If the CO content deviates from the specified value, remove the seal from the CO content adjustment screw. To do this, pierce the plastic cap in the middle, screw in the appropriate screw or self-tapping screw and pull out the screw together with the seal. If necessary, remove the air filter and install it again.
Adjust the set CO content value by turning the adjusting screw.
Place a new filling.
Turn off the measuring instruments.
Connect the engine crankcase ventilation hose.