10
NOTE: The engine should be warm (operating tem-
perature) and the battery fully charged for an accurate
compression test. On the XT/XTX, throttle must be in
the wide-open throttle (WOT) position. In the event the
engine cannot be run, cold values are included.
NOTE: The seats and center console must be
removed for this procedure.
1. Remove the high tension lead from the spark plug(s).
2. Using compressed air, blow any debris from around
the spark plug(s).
3. Remove the spark plug(s); then attach the high tension
lead(s) to the plug(s) and ground the plug(s) on the cyl-
inder head(s) well away from the spark plug hole(s).
4. Attach the Compression Tester Kit.
5. While holding the throttle in the full-open position,
crank the engine over with the electric starter until
the gauge stops climbing (five to 10 compression
strokes).
6. If compression is abnormally low, verify the
following items.
A. Starter cranks engine over.
B. Gauge is functioning properly.
C. Throttle in the full-open position.
D. Valve/tappet clearance correct.
E. Engine warmed up.
F. Intake not restricted.
NOTE: To service top-side components, see the
Engine/Transmission section.
7. Pour approximately 30 ml (1 fl oz) of oil into the
spark plug hole(s), reattach the gauge, and retest
compression.
8. If compression increases to normal, service the pis-
ton rings (see the appropriate Engine/Transmission -
Top side Components).
Spark Plug(s)
A light brown insulator indicates that the plug is correct.
A white or dark insulator indicates that the engine may
need to be serviced. To maintain a hot, strong spark, keep
the plug free of carbon.
ATV-0051
Adjust the gap to 0.5-0.6 mm (0.019-0.024 in.).
ATV0052E
When installing a spark plug, be sure to tighten it
securely. A new spark plug should be tightened 1/2 turn
once the washer contacts the cylinder head. A used spark
plug should be tightened 1/8-1/4 turn once the washer
contacts the cylinder head.
Muffler/Spark Arrester
Clean the spark arrester using the following procedure.
1. Remove the cap screws securing the spark arrester
screen assembly to the muffler; then loosen and
remove the spark arrester. Account for a gasket.
! WARNING
Always wear safety glasses when using compressed air.
Model
PSI Hot (WOT)
PSI Cold (WOT)
XT
120-140
80-120
XTX
125-145
100-140
XTZ (Front)
125-145
80-120
XTZ (Rear)
165-185
150-190
CAUTION
Before removing a spark plug, be sure to clean the area
around the spark plug. Dirt could enter engine when
removing or installing the spark plug.
! WARNING
Wait until the muffler cools to avoid burns.