Connect the stroboscope in accordance with the instruction manual, while attaching the stroboscope sensor clamp to the high-voltage wire of the ignition coil.
Disconnect the vacuum hose from the sensor-distributor.
Check the engine crankshaft speed.
Aim the flashing strobe light at the scale on the camshaft cover. If the ignition timing is set correctly, then when the engine is idling, the mark on the crankshaft pulley should be opposite the 4th division of the scale.
To adjust the ignition timing, stop the engine, loosen the ignition distribution sensor fastening nuts and turn it to the required angle.
Tighten the fastening nuts and check the ignition timing again.
Disconnect the stroboscope.
Attach a vacuum hose to the sensor-distributor.
Check engine idle.