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3.
Valve clearance
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The valve clearance should be inspected and adjusted on a cold
engine by the following procedures:
-
Remove the caps of the central port and the ignition timing
observation port on the left crankcase cover.
-
Remove the caps of the valves on the cylinder head.
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Turn the nut of the flywheel clockwise until the engraved "T" mark
on the flywheel aligns with the engraved line on the top of the
crankcase cover, and both intake and exhaust rocker arms do not
move but stop at their loosest position. This indicates that the
piston is in its top dead center position of the compressing stroke.
If the "T" mark is near the proper position but the rocker arms will
move when the flywheel rotates within a small angle, the flywheel
is not on the compression stroke but exhaust/intake stroke. In this
case, continue to turn the flywheel clockwise 360 degrees to reach
top dead center position of the compressing stroke, where the
valve clearance can be adjusted.
-
Check the valve clearance by inserting a clearance gage into the
gap between adjusting screw and the end of the valve.
Valve Adjustment
Specified valve clearance:
Intake: 0.07-0.10mm Exhaust: 0.08-0.12mm
If valve clearance adjustment is needed, loosen the locking nut on
the rocker arm, insert the proper clearance gauge and turn the
adjusting nut until a slight resistance is felt on the inserted
clearance gage.
After adjustment, tighten the locking nut to prevent loosening and
re-insert the valve gauge to re-check the valve clearance.
Reinstall the valve covers once final adjustment has been made.
Eyehole cover
Upper eyehole cover
