APRILIA RS 125 - 1996 Manual page 71

If the spark plug has crackings on the insulating ma-
terial, corroded electrodes or excessive deposits, it
must be changed.
– Check the spark plug gap (Fig. 50) with a thickness
gauge. The gap must be about 0,5 mm; if neces-
sary adjust it, carefully bending the earth electrode.
– Make sure that the washer is in good conditions.
With the washer on, screw the spark plug by hand
in order not to damage the thread.
– Tighten the spark plug by means of the spanner,
giving it half a turn to compress the washer.
– Put back the spark plug cap.
b
The spark plug must be well tightened,
otherwise the engine may overheat and
be seriously damaged. Use the suggested
type of spark plug only (see "TECHNICAL DATA"
- page 83), in order not to compromise the life
and performance of the engine.
Fig. 50
71