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5. Adjusting the valve clearance
CAUTION: Be sure to adjust the valve clearance with the engine sufficiently cooled down.
(1) Remove the two Screws
[101]
and upper Screw
M4 x 25
[87]
fixing the Recoil Starter
[85]
, and then
remove the Engine Cover
[102]
or
[104]
.
(2) Remove the Bolt M5 x 20
[115]
, and then remove the Fan Case
[112]
.
(3) Remove the Bolt M4 x 10
[27]
, and then remove the Cylinder Head Cover
[28]
. If the Cylinder Head
Cover
[28]
cannot be easily removed due to liquid packing applied between the Cylinder Head Cover
[28]
and Cylinder (A)
[38]
, use a plastic hammer to lightly hit the side of the Cylinder Head Cover
[28]
.
Be careful not to deform the Cylinder Head Cover
[28]
by hitting it.
(4) Remove the Spark Plug (TORCH CMR5H)
[18]
.
(5) Slowly rotate the Magneto Rotor
[122]
counterclockwise. After the Exhaust Valve
[41]
and Intake Valve
[40]
operate sequentially in this order, while looking through the Spark Plug (TORCH CMR5H)
[18]
mounting hole on Cylinder (A)
[38]
, rotate the Magneto Rotor
[122]
by a half turn until the Piston
[51]
is
positioned at the top dead center.
(6) Insert a feeler gauge between the Rocker Arm
[34]
and Exhaust Valve
[41]
, and between the Rocker
Arm
[34]
and Intake Valve
[40]
to check the valve clearance. Adjust the valve clearance if it is out of
the range from 0.1 to 0.2 mm.
(7) Use a wrench to fix the lower Nut M5
[29]
onto the Shaft Bolt
[35]
. In this status, loosen the upper Nut
M5
[29]
, and then loosen the lower Nut M5
[29]
.
NOTE: Loosening the upper Nut M5 [29] without the lower Nut M5 [29] being fixed will loosen
the Shaft Bolt [35]. Therefore, be sure to fix the lower Nut M5 [29] before loosening the
upper Nut M5 [29].
(8) Insert a 0.35-mm feeler gauge between the Rocker Arm
[34]
and Exhaust Valve
[41]
or Intake Valve
[40]
. In this status, tighten the lower Nut M5
[29]
until it lightly touches the Pivot Rocker Arm
[30]
. Then,
while fixing the lower Nut M5
[29]
so that it does not turn, tighten the upper Nut M5
[29]
with torque of
3.5 ± 0.5 N·m.
(9) Pull the starter knob several times, position the Piston
[51]
at the top dead center as described in step
(5) above, and then use a feeler gauge to check whether the valve clearance is 0.1 to 0.2 mm.
NOTE: If the lower Nut M5 [29] turns while the upper Nut M5 [29] is being tightened, the
adjusted valve clearance may exceed the range from 0.1 to 0.2 mm. Therefore, be sure
to use a wrench to fix the lower Nut M5 [29] before tightening the upper Nut M5 [29].
• Adjusting the valve clearance
Exhaust valve side
Intake valve side
