Testing Engine Compression; Spark Plug - Arctic Cat ROV 2013 Service Manual

Valve Adjuster Procedure
A. Place the Valve Clearance Adjuster onto the jam
nut securing the tappet adjuster screw; then rotate
the valve adjuster dial clockwise until the end is
seated in the tappet adjuster screw.
B. While holding the valve adjuster dial in place, use
the valve adjuster handle and loosen the jam nut;
then rotate the tappet adjuster screw clockwise
until friction is felt.
C. Align the valve adjuster handle with one of the
marks on the valve adjuster dial.
D. While holding the valve adjuster handle in place,
rotate the valve adjuster dial counterclockwise
until proper valve/tappet clearance is attained.
NOTE: Refer to the specifications in Feeler
Gauge Procedure sub-section for the proper valve/
tappet clearance.
NOTE: Rotating the valve adjuster dial counter-
clockwise will open the valve/tappet clearance by
0.05 mm (0.002 in.) per mark.
E. While holding the adjuster dial at the proper
clearance setting, tighten the jam nut securely
with the valve adjuster handle.
3. Install the spark plug; then install the timing inspec-
tion plug.
4. Place the two tappet covers with O-rings into posi-
tion. Tighten the cap screws to 9 ft-lb.
Testing Engine
Compression
To test engine compression, use the following procedure.
NOTE: The engine should be warm (operating
temperature) and the battery fully charged for an
accurate compression test. The throttle must be in
the wide-open throttle (WOT) position. In the event
the engine cannot be run, cold values are
included.
NOTE: The seat, seat back, and seat base must
be removed for this procedure.
1. Remove the high tension lead from the spark plug.
2. Using compressed air, blow any debris from around
the spark plug.
Always wear safety glasses when using compressed
air.
3. Remove the spark plug; then attach the high tension
lead to the plug and ground the plug on the cylinder
head well away from the spark plug hole.
CC007D
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).
PSI Hot (WOT)
125-145
6. If compression is abnormally low, inspect 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 obstructed.
 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, reattach the gauge, and retest com-
pression.
8. If compression is now evident, service the piston
rings (see the Engine/Transmission section).
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.
! WARNING
PSI Cold (WOT)
100-140

Spark Plug

9