YG125-30A Maintenance Manual
Cylinder Head, Cylinder and Piston
54
Top planeness
/
0.05
Piston and piston
pin
Piston external
diameter
φ
52.37
~φ
52.39mm mm
φ
52.37mm
Fit clearance with
cylinder
0.01mm
~
0.04mm
0.04mm
Piston pin external
diameter
φ
12.995mm
~φ
13mm
φ
12.995mm
Piston pin hole
inside diameter
φ
13.002mm
~φ
13.008mm
φ
13.008mm
Fit clearance
0.002mm
~
0.013mm
0.013mm
Connecting rod
small end
Internal diameter
φ
13.013mm
~φ
13.028mm
φ
13.028mm
Clearance with
piston pin
0.013mm
~
0.033mm
0.033mm
Piston ring
First ring gap
clearance
0.015mm
~
0.05mm
0.05mm
Second ring gap
clearance
0.015mm
~
0.05mm
0.05mm
First ring side
clearance
0.002mm
~
0.013mm
0.013mm
Second ring side
clearance
0.002mm
~
0.013mm
0.013mm
Oil ring side
clearance
0.002mm
~
0.013mm
0.013mm
Key torque values
Cylinder head cover connecting bolt 8-12 N.m
Cylinder bolt 40-50 N.m
Timing driven sprocket bolt 8-12 N.m
Spark plug 18-25 N.m
Pensioner plate fastening bolt 8-12 N.m
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