Operation Manual

11. Crankcase / Crankshaft
11-2
Operational Precautions
General information
y This Section contains descriptions concerning disassembly of the crankcase so that the crankshaft can
be serviced.
y Complete following operations before disassembling crankcase.
Engine Chapter 5
Cylinder head Chapter 6
Cylinder and piston Chapter 7
V-belt Drive pulley Chapter 8
Alternator/Foot Starting Clutch Chapter 10
Start motor Chapter 16
y If the crankshaft bearing or timing sprocket need be replaced, then the crankshaft set have to replaced.
Specification Unit: mm
Item Standard Limit
Left, right clearance of the big end of the connecting rod
0.100~0.300 0.550
Right angle clearance of the big end of the connecting rod
0.000~0.008 0.050
Run-out
─
0.100
Torque value
Bolts for crankcase 1.5 ~ 2.0kgf-m
Bolts for cylinder/cylinder head 0.7 ~ 1.0kgf-m
Engine oil draining plug 3.5 ~ 4.5kgf-m
Bolts for cam chain tensioner 0.8 ~ 1.2kgf-m
Special Service Tools
Oil seal (25X37X6) pressing tools SYM-9121600
Trouble Diagnosis
Engine noise
y Loose crankshaft bearing
y Loose crankshaft pin bearing
y Wear piston pin or piston pin hole
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