Warm up and turn off the engine. The oil temperature must be at least 60°.
Switch off electrical consumers.
Check the condition of the air filter insert (see section «Removal and installation of the air filter»).
Connect devices for measuring the number of revolutions and CO content in accordance with the instructions for their operation; the air filter remains removed.
Disconnect the crankcase breather hose.
Start the engine at idle speed.
Check intake system for leaks. To do this, cover with gasoline all the connections of the intake device with a brush. If at the same time briefly increase the engine speed, then 8 leaky places will be sucked in air. Locate and eliminate leaks.
Attention: Do not inhale fuel vapors - poison! Avoid splashing gasoline on hot parts and on the ignition system. Fire hazard!
Check engine idle speed. Setpoint see table in section «Ignition system».
In case of deviations, find and eliminate the fault according to the fault diagnosis table.
Check CO content. Setpoint see table in section «Ignition system».
In case of deviations from the set value of the CO content, remove the seal from the CO content adjusting screw. To do this, pierce the plastic cap in the middle, screw in the corresponding screw or self-tapping screw and pull out the screw together with the seal. If required, remove the air filter and install again.
Adjust the set value of the CO content by turning the adjusting screw.
Place a new filling.
Turn off meters.
Connect the crankcase breather hose.