Sym SYM series, Manual, Page: 27 / 178

11. CRANKCASE/CRANKSHAFT SYM
11-2
OPERATIONAL PRECAUTIONS
General Information
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This Section contains descriptions concerning disassembly of the crankcase so that the
crankshaft can be serviced.
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Complete following operations before disassembling crankcase.
Engine Chapter 5
Cylinder head Chapter 6
Cylinder and piston Chapter 7
V-belt Drive pulley Chapter 8
AC generator/ Starting Clutch Chapter 10
Start motor Chapter 16
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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
0.100~0.350 0.550
Radial clearance of the big end of
the connecting rod
0.000~0.008 0.050
Run-out
Left side: Below 0.035
Right side: Below 0.035
Left side: 0.035
Right side: 0.030
Torque value
Bolts for crankcase 1.5~2.0 kgf-m
Bolts for cylinder/cylinder head 0.7~1.0 kgf-m
Engine oil draining plug 3.5~4.5 kgf-m
Bolts for cam chain tensioner 0.8~1.2 kgf-m
Special Service Tools
Crankcase remover/set
Crankshaft installation puller
Inner type bearing puller
Outer type bearing puller
Bearing pressing tools
Oil seal pressing tools
TROUBLE DIAGNOSIS
Engine noise
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Loose crankshaft bearing
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Loose crankshaft pin bearing
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Wear piston pin or piston pin hole