APRILIA QUASAR 125 2003, Workshop Manual

Page: 35 / 168

PERIODIC MAINTENANCE
QUASAR 125-180
2 - 10 -
00
Release 00/2003 - 09
1
2.7 SPARK PLUG
Read carefully 1.3 (GENERAL SAFETY RULES).
Check the spark plug every six months, remove carbon deposits and replace if
necessary.
Removal and cleaning.
Before carrying out the following operations, let the engine and the
exhaust pipe cool down until they reach room temperature, in order to
avoid burns.
Never remove a spark plug cap while the engine is running. Shock
hazard.
"
Remove the spark plug cap (1).
"
Remove any trace of dirt from the spark plug base.
"
Unscrew the spark plug and extract it from its seat, taking care to prevent
dust or other substances from getting inside the cylinder.
"
Make sure that there are neither carbon deposits, nor corrosion marks on
the electrode and on the spark plugs ceramics; if necessary, clean with a
plug cleaner or wire brush.
Blow out with compressed air to stop residues getting into the engine itself.
If the spark plug has crackings on the insulating material, corroded electrodes
or excessive deposits, it must be changed.
Check the electrode gap with a thickness gauge.
Electrode gap should be
0.6 -0.7 mm ( 0.02-0.03 in ). If it needs adjusting,
bend the earth electrode carefully.
Make sure the washer is in good condition. Fit the washer and screw the spark
plug finger-tight to avoid damaging the thread.
Tighten the spark plug by means of the spanner you will find in the tool kit,
giving it half a turn to compress the washer. Unscrew and tighten to the
prescribed torque.
Spark plug torque: 19 Nm (1.9 kgm).
The spark plug must be well tightened, otherwise the engine may
overheat and be seriously damaged. Replace only with spark plugs of
the type indicated in this manual.
Position the spark plug cap properly, so that it does not come off due to the
vibrations of the engine.
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