2-7
2
GZ063
NOTE: At this point, the rocker arms and adjuster
screws must not have pressure on them.
NOTE: Use Valve Clearance Adjuster for this pro-
cedure.
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.
8. Rotate the engine 270° to the TDC position of the
rear cylinder; then repeat steps 4-7 for the rear
cylinder.
9. Place the tappet covers with O-rings into position;
then tighten the covers securely.
10. Install the spark plugs; then install the timing
inspection plug and crankshaft end cap.
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.
3. Remove the spark plugs; then attach the high ten-
sion lead to the plugs and ground the plug on the
cylinder heads well away from the spark plug
hole.
4. Attach the Compression Tester Kit to the cylinder
to be tested.
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).
6. If compression is abnormally low, inspect the
following items.
A. Verify starter cranks engine over at normal
speed (approximately 400 RPM).
B. Gauge functioning properly.
C. Throttle lever in the full-open position.
D. Valve/tappet clearance correct.
E. Valve not bent or burned.
F. Valve seat not burned.
NOTE: To service valves, see Section 3.
7. Pour 29.5 ml (1 fl oz) of oil into the spark plug
holes, reattach the gauge, and retest compression.
8. If compression is now evident, service the piston
rings (see Section 3).
! WARNING
Always wear safety glasses when using compressed
air.
PEAK COMPRESSION
CYLINDER
PSI
Front
75-85
Rear
120-130
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