Examination
Make sure the correct spark plugs are installed. Incorrect spark plug type causes deterioration in engine controllability.
Make sure the spark plug has the correct glow rating. Installing a candle with an incorrect glow number leads to:
- dirty spark plug, replace with a hotter spark plug;
- spark plug or engine damage, replace with a cooler spark plug.
Inspect the terminal (1) spark plug wire, look for signs of damage. Check the tightness of the terminal (it shouldn't rotate).
Examine the insulator (2), look for cracks or soot deposits. Cracks or soot leads to breakdown between the terminal (1) And "earth" instead of breakdown between electrodes (3) And (4).
Measure the gap between the center electrode (4) and side electrode (3). An excessively large gap can cause the spark plug to run irregularly.
Shake the candle: a rattling sound indicates internal damage to the candle (loose fit of the center electrode (4) reduces the power of the spark discharge).
Checking spark plugs | 
Measurement of the gap between the central and side electrodes |
Inspect the area of the spark plug protruding from the cylinder head. Dirty or damaged threads indicate incorrect spark plug installation.
During normal operation of the candle, the color of the insulator changes from gray-yellow to brown with small inclusions of a powdery substance (combustion products of additives in fuel and oil).
Dry and fluffy carbon deposits can be caused by:
- A) Rich air-fuel mixture
- leaking nozzles
- excessive fuel pressure
- dirty air filter
- improper combustion
- b) Low output voltage
- ignition coil defect
- defective spark plug wires
- incorrect gap between spark plug electrodes
- V) Continuous idling or low speed operation.
Withdrawal
1. Remove wire from spark plug.
- A) Rotate the spark plug wire boot half a turn.
- b) Pulling on the cover, remove the wire.
2. Clean the area around the spark plug.
3. Remove the spark plug. When removing several candles, mark their installation locations.
Installation
1. Check that the spark plug sealing washer is present and correctly installed.
2. Check the gap between the spark plug electrodes, adjust if necessary.
3. Wrap the candle by hand until it stops.
4. Tighten the spark plug. Tightening torque 15 Nm.
5. Install the spark plug wire.
6. Check the correct installation of the wire - squeeze the sides of the cover and make sure it is tight.