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iii) Check the balancing of the crankshaft using a dial indicator (see
Fig.13). If the value is more than 0.100, replace the crankshaft
assembly.
iv) Measure the big end of the connecting rod our of round with a
dial indicator. In case the value is more than 0.120, replace the
crankshaft assembly.
v) To check the play of the small end of connecting rod, put a piston
pin in the small end and measure the play of the piston pin with a
dial indicator. In case the value is more than 0.050, replace the
connecting rod.
⑥
Inspection and maintenance of the ball bearings
Dismount the ball bearings out of the crankcase or the housing when you check them.
i) Wash the ball bearings with kerosene or gasoline. Before starting the work, follow the instructions (16)
~
(19) in “3. Notification
on inspection, maintenance, and repair of the engine” in this manual (page 4)
WARNING
When you wash the parts with gasoline or kerosene, carry out the work only outdoors or in well ventilated
area away from any source of fire to prevent a fire.
ii) Check the ball bearings for damages with a magnifying glass, outer rings, inner rings, balls, and cages. You
can inspect balls and cages only for open type ball bearings. Replace the bearings in case there are
damages.
iii) Hold the bearing horizontally in one hand, and then rotate the outer ring to confirm that it turns smoothly.
Replace the ball bearing if it does not turn smoothly. Ball bearings are important parts in the engine, so
replace immediately when you find something abnormal.
⑦
Inspection and maintenance of the carburetor
Some parts cannot be assembled upside down, left side right, or inside out even they look the same. Follow
the instructions (16)
~
(19) in “3. Notification
on inspection, maintenance, and repair of the engine” in this
manual (page 4).
i) Dismount the carburetor from the engine to wash with kerosene or gasoline. Do not blow compressed air
so close not to give damage on the internal parts.
WARNING
When you wash the part with gasoline or kerosene, carry out the work only outdoors or in well ventilated
area away from any source of fire to prevent a fire.
ii) Check the carburetor for damages and missing parts. Replace the part if there are damages.
iii) Move the throttle arm and the choke arm from the fully close position to the fully open position to check it
moves smoothly without looseness. Replace the part if it does not move smoothly without looseness.
iv) In case the engine does not work well after adjustment of the carburetor, remove the 4 screws, Plate 1,
Sheet 1, and 2 (See Fig.14). Take out the mesh in Part A in Fig.14 and wash off the dust with kerosene or
gasoline, or blow off the dust with compressed air. Check Sheet 1 and 2 (Fig.14) for any deformation and
hardening. Replace it in case of deformation and hardening. Reassemble the carburetor placing the parts
Summary of Contents for GT120THU
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