Cleaning And Replacing The Spark Plugs - Ducati MONSTER S4R Manuel D'utilisation Et Entretien

Cleaning and replacing the spark plugs (fig. 63)
Spark plugs are essential to smooth engine running and
should be checked at regular intervals.
The operation is relatively simple and spark plug condition
provides a good measure of engine condition.
Extract the coils from the plugs and remove them from the
head with the provided wrench.
Check the colour of the ceramic surround of the central
electrode: a light brown, even color is a sign of good
engine condition.
If the colour is different or the unit is covered with a dark
crust, replace the spark plug and notify a Ducati Dealer or
Authorised Workshop.
Also check the wear of the central electrode; if it is worn
or glassy, replace the unit.
Check the electrode gap, which must be in the range:
0.6-0.7 mm.
Important
If adjustment is required, bend the lateral electrode
only. An electrode gap outside the specified limit will
adversely affect engine performance and may lead to
difficult starting or erratic idling.
Carefully clean the electrode and ceramic surround with a
wire brush and check the condition of the gasket.
Clean the spark plug socket on the head and take care
not to allow foreign bodies to fall into the combustion
chamber.
Reinstall the spark plug to the head and screw it fully down.
Lock down to 20 Nm.
If you do not have a torque wrench, after tightening by
hand, turn the unit a further half turn with the provided
wrench.
Important
Do not use spark plugs with an unsuitable heat rating
or incorrect thread length.
The spark plug must be correctly inserted and locked down.
E
fig. 63
61