Can-Am DS 450 2008 Shop Manual page 257

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CLEAN AREA AROUND SPARK PLUGS
Using an approved spark plug socket, release the
spark plug torque.
1. Proper socket
2. Improper socket
Remove wrench from socket and extension and
unscrew the spark plug by hand.
Troubleshooting a Fouled Spark Plug
Fouling of the spark plug is indicated by irregular
running or misfiring of the engine, decreased
engine speed due to misfiring, reduced perfor-
mance, and increased fuel consumption. This
may be due to a loss of compression.
Other possible causes are: a clogged air filter, in-
correct or bad fuel, defective ignition system, in-
correct spark plug gap, lubricating oil entering the
combustion chamber, or use of a spark plug with a
temperature rating too cold for the engine require-
ment.
The plug face of a fouled spark plug has either a
wet or dry black carbon deposit. Such coatings
form a conductive connection between the center
electrode and the ground electrode.
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Section 06 ELECTRICAL SYSTEM
Subsection 01 (IGNITION SYSTEM)
Spark Plug Analysis
TYPICAL
1. Overheated (light grey, white)
2. Normal (light brown, brown)
3. Fouled (black, wet or dry, dark deposits, grey, melted coating)
The plug face reveals the condition of the engine,
operating condition, method of driving and fuel
mixture. For this reason it is advisable to inspect
the spark plug at prescribed intervals, examining
the plug face (i.e. the part of the plug projecting
into the combustion chamber).
Spark Plug Installation
Spark plug installation is the reverse of the re-
moval procedure. However, pay attention to the
following.
Prior to installation make sure that contact sur-
faces of the cylinder head and spark plugs are free
of grime.
Using a wire type feeler gauge, set the electrode
gap as specified in TECHNICAL SPECIFICATIONS
Apply a light coat of heat-sink paste (P/N 420 897
186) over the spark plug threads and gasket to
ensure proper cooling of the spark plugs.
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1. Apply heat-sink paste
CAUTION: Not applying heat-sink paste to the
spark plug threads and gasket as recommend-
ed can cause premature spark plug failure due
to insufficient heat transfer.
Hand screw spark plug into cylinder head until it
bottoms out.
Torque spark plug to 19 N•m (168 lbf•in) using an
approved spark plug socket and torque wrench.
.
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