When operating a car, sometimes, depending on the quality of the fuel being refueled, it becomes necessary to adjust the ignition timing. Carry out the adjustment on a warm engine. While driving on a level road in direct gear at a speed of 50 km/h, depress the accelerator pedal sharply. If this causes a slight and short-term detonation, then the ignition timing is set correctly. With strong detonation (early ignition) mark the position of the middle risk of the scale 3 (pic. 19) on the cylinder block, loosen nut 1 and turn the housing 2 of the ignition distributor 0.5-1 division clockwise (on «—»). If there is no detonation (late ignition) turn housing 2 0.5-1 division counterclockwise (on «+»).
Pic. 19. Octane corrector:
1 - nut; 2 - housing of the ignition distributor; 3 - scale.
After adjustment, tighten nut 1 and check again for correct ignition timing while driving.