7.1.6. Engine diagnostics on a condition of spark plugs
The condition of the engine can be estimated by the form deposits on an insulator of the central electrode.
Check of spark plugs (when the cranked shaft of the engine can be scrolled by a starter)
Connect a candle wire of a high voltage to the spark plug which has been turned out from a head of cylinders. Connect an external electrode (case) of a candle to "weight" (with an arm on the engine), scroll a cranked shaft of the engine a starter. If the candle is serviceable, between electrodes of a spark plug the spark (quite weak as the category passes in the atmosphere at a small gap) will slip. If the spark plug is faulty, the spark will not appear because of leakage of a charge on a candle insulator (fig. 7.6)
Check of candle wires of a high voltage
Check a cap and wire isolation on lack of cracks.
Fig. 7.7. Scheme of measurement of resistance of a candle wire
Resistance of a candle wire of a high voltage should not be higher than 10 kiloohms (BOUGI) or 22 kiloohms (R16AIPS) on meter of length of a wire. If resistance of a wire is higher than the specified size, replace a wire.