Cleaning And Replacing The Spark Plugs - Monster 659 Owner's Manual

Cleaning and replacing the spark plugs

E
Spark plugs are essential to smooth engine running and
should be checked at regular intervals.
This is a relatively simple operation and provides a good
indication of how well the engine is running.
Pull the spark plug caps off the spark plugs and remove the
plugs from the cylinder heads using the wrench supplied in
the toolkit.
Check the colour of the ceramic insulation around the central
electrode: a uniform light brown colour indicates good
engine condition.
If the insulation is any other colour, or if there are dark
deposits, replace the spark plug and describe the condition
of the old plug to a Ducati dealer or Authorized Ducati Service
Centre.
Also check the central electrode; if it is worn or glazed,
replace the spark plug.
Check the distance between the electrodes, which must be:
0.7 - 0.8 mm.
Important
If adjustment is required, bend the side electrode
carefully. If gap is too wide or too close, engine performance
will be affected. This could also cause difficult starting or
irregular idling.
Thoroughly clean the electrode and insulation using a wire
brush, and check the condition of the gasket.
Carefully clean the seat in the cylinder head and be careful
not to let any foreign material fall into the combustion
chamber.
106
Insert the spark plug in the cylinder head and screw in fully
by hand. Tighten to a torque of 20 Nm.
If you do not have a torque wrench, after hand-tightening the
spark plug, turn it an additional half turn with the wrench
provided in the tool kit.
Important
Do not use spark plugs with an unsuitable heat rating
or incorrect reach.
The spark plug must be tightened correctly.
0,7÷0,8 mm
fig. 112