2
EN- 23
SPECIFICATIONS - OPERATION - MAINTENANCE
EN
SPARK PLUG CHECK
Use NGK BR8EG spark plug (2); the gap is 0,6÷0,7 in.
A wider gap may cause difficulties in starting engine and in
overloading coil.
A gap that is too narrow may cause difficulties when accelerat-
ing, when idling the engine or when performing at low
speeds.
Clean the dirt away from the base of the spark plug before re-
moving it from the cylinder after removing the cap (1).
It is very useful to examine the state of the spark plug just after it
has been removed from the engine since the deposits on the plug
and the colour of the insulator provide useful indications.
Correct heat rating:
The tip of the insulator should be dry and the colour should be light
brown or grey.
High heat rating:
In this case, the insulator tip is dry and covered with dark deposits.
low heat rating:
In this case, the spark plug is overheated and insulator tip is vitre-
ous, white or grey in colour.
CAUTION*: Select a spark plug with a colder
or hotter heat range carefully and cautiou
-
sly. A spark plug with too hot a heat range
may lead to preignition and possible engine
damage. A spark plug with too cold a heat
range may foul as the result of too much car
-
bon buildup.
Before refitting the plug, thoroughly cle
-
an the electrodes and the insulator using a
brass-metal brush.
Apply a little graphite grease to the spark
plug thread; fit and screw the spark plug by
hand then tighten to the torque of 23,5÷25,5
Nm- 17,3÷18,8 ft/lb.
Spark plugs which have cracked insulators or
corroded electrodes should be replaced.
