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.
Checking the characteristics of the centrifugal ignition timing controller on a car
Check ignition timing.
Disconnect the vacuum hose from the sensor-distributor.
Connect a phase shift stroboscope between the high voltage wire of the 1st cylinder and the tachometer.
Taking division 0 of the ignition angle setting scale as a reference point, check the characteristic of the centrifugal regulator according to the graph given in subsection «Detailed Specifications».
If the characteristic differs from the given one, check the ignition distribution sensor on the stand.
Checking the characteristics of the vacuum ignition timing controller on a car
Check the performance of the centrifugal ignition timing controller (see above).
Connect a vacuum pump to the regulator vacuum connection.
Set the crankshaft speed to 2500 rpm and determine the value of the ignition timing with the centrifugal regulator in degrees relative to the zero division of the scale.
Set the vacuum values according to the schedule given in subsection «Detailed Specifications» and set the crankshaft speed to 2500 rpm.
Measure the ignition advance angle and determine the ignition advance angle provided by the vacuum regulator by subtracting the amount of ignition advance relative to the zero division of the scale from the obtained value.
If the value obtained does not correspond to that shown on the graph, check the ignition distribution sensor on the stand.