SECTION 3. MAINTENANCE
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3-7 Valve Clearance
Valve clearance inspection and
adjustment must be performed with the engine
cold.
1) Remove the cylinder head cover, and set the
piston at top dead center of the compression
stroke (both valves fully closed). Pull the starter
until the piston is at top dead center of the
compression or exhaust stroke.
2) Insert a feeler gauge between the rocker arm
and valve to measure valve clearance.
3) If adjustment is necessary, proceed as follows:
a) Hold the rocker arm pivot and loosen the
pivot lock nut.
b) Turn the rocker arm pivot to obtain the
specified clearance.
c) Retighten the lock nut while holding the
rocker arm pivot.
d) Recheck valve clearance after tightening
the lock nut.
3-8 Governor
1) Take down the fuel tank.
2) Loosen the nut on the governor arm pinch bolt.
3) Move the arm until the throttle is completely
open, and hold it in that position.
4) Rotate the governor arm shaft as far as it will
go in same direction it was just moved by the
governor arm, and then tighten the governor arm
pinch bolt.
5) Whether Check the arm and throttle move
smoothing.
6) Install the fuel tank.
7) Start the engine and adjust the limiting screw to
produce the standard until the engine warm up to
normal operating temperature.
Standard valve
clearance
IN.
0.10±0.02 mm
(0.004±0.001 in)
EX.
0.15±0.02 mm
(0.006±0.001 in)
Idle speed
3600
±
150rpm
FEELER
GAUGE
GOVERNOR
SPRING
THROTTLE
GOVERNOR
ARM SHAFT
GOVERNOR
ARM
ANTI-SURGE
SPRING
NUT
LIMITING
SCREW
GOVERNOR
ARM PINCH
BOLT
ROCKER ARM
PIVOT
To increase valve clearance, screw lock nut out.
To decrease valve clearance, screw lock nut in.
LOCK NUT
10N
•
m-140N
•
m
