Valve/Tappet Clearance (Valve Adjuster Procedure); Testing Engine Compression - Arctic Cat 650 Twin2004 Service Manual

Valve/Tappet Clearance
(Valve Adjuster Procedure)
To check and adjust valve/tappet clearance, use the
following procedure.

NOTE: The seat, air filter housing, front fenders,
front inner covers, and side panels must be
removed for this procedure.
1. Remove the cap screws securing the recoil starter;
then remove the recoil starter assembly.
2. Remove the timing inspection plug; then remove
the four tappet covers (for more detailed informa-
tion, see Section 3 - Servicing Top-Side Compo-
nents).
3. Rotate the crankshaft counterclockwise to the
TDC position on the compression stroke indicated
by the TF mark on the flywheel. TF is top dead
center front.

NOTE: At this point, the rocker arms and
adjuster screws must not have pressure on them.

NOTE: Use Valve Gap Adjuster (p/n 0444-092) for
this procedure.
3. Place the valve 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.
4. 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.
5. Align the valve adjuster handle with one of the
marks on the valve adjuster dial.
6. 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 appropriate 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.
7. While holding the adjuster dial at the proper clear-
ance setting, tighten the jam nut securely with the
valve adjuster handle; then tighten the jam nuts to
1.2 kg-m (104 in.-lb).
8. Rotate the crankshaft counterclockwise until the
TR mark aligns in the timing hole; then repeat
steps 3-7 for the rear cylinder.
9. Install the timing inspection plug; then install the
four tappet covers and tighten securely.
10. Install the recoil starter assembly and tighten the
cap screws securely.
11. Install the air filter housing, front inner covers,
front fenders, and side panels; then install the seat
and make sure it locks securely.
Testing Engine
Compression
To test engine compression, use the following proce-
dure.
1. Remove the high tension leads from the spark
plugs.
2. Using compressed air, blow any debris from
around the spark plugs.
! WARNING
Always wear safety glasses when using com-
pressed air.
3. Remove the spark plugs; then attach the high ten-
sion leads to the plugs and ground the plugs on the
cylinder head well away from the spark plug
holes.
4. Attach the Compression Gauge (p/n 0444-096) to
the front or rear cylinder.

NOTE: The engine must be warm and the battery
must be fully charged for this test.
5. While holding the throttle lever in the full-open
position, crank the engine over with the electric
starter until the gauge shows a peak reading (five
to 10 compression strokes).

NOTE: The compression should be within a
range of 47-81 psi in the full-open throttle position.
6. Repeat for the second cylinder.
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