Switch off electrical consumers.
Check the condition of the air filter element (see section «Removal and installation of the air filter»).
Connect instruments for measuring the number of revolutions and CO content in accordance with their operating instructions; the air filter remains removed.
Caution: The crankcase breather hose remains connected.
Start the engine at idle speed.
Check the ignition timing and, if necessary, adjust (see section «Checking and adjusting the ignition timing»).
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 air will be sucked in in loose places. 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»).