1. On models of engines with 16 valves, to access the spark plugs, you must first remove the casing located in the center of the cylinder head. To remove the cover, unscrew the eight bolts (indicated by arrows), marking the position of the electrical wiring and retaining clip.
2. On models with a working volume of 1998 cm33 with 16 valves, spread the high voltage wires from the spark plugs.
3. Before removing plugs of high-voltage wires from spark plugs, remove dirt using a clean brush, vacuum cleaner or compressed air to prevent dirt from entering the engine cylinders.
4. Checking the spark plugs shows the condition of the engine. If the nose of the spark plug insulator is clean and white, this indicates that the mixture is too lean or "hot" spark plug. If the tip and nose of the insulator are covered with a hard black coating, this indicates that the mixture is too rich. If it's black and oily, the engine is probably worn out. If the nose of the insulator has a slight light brown coating, then the mixture is optimal and the engine is probably in good condition.
5. Measure the spark plug gap with a feeler gauge. The gap between the electrodes of the spark plug is important, because if the gap is too large or too small, the ignition spark size and efficiency will not be sufficient for normal engine operation.
6. To set the interelectrode gap, bend the outer electrode until the required gap is obtained. Never bend the center electrode, as this could crack the insulator.
7. Connect high-voltage wires in a strictly defined order.