Trouble Diagnosis - Sym ALA125CC Manual

11. CRANKCASE/CRANKSHAFT
OPERATIONAL PRECAUTIONS
General Information
This Section contains descriptions concerning disassembly of the crankcase so that the
crankshaft can be serviced.
Complete following operations before disassembling crankcase.
Engine
Cylinder head
Cylinder and piston
V-belt Drive pulley
AC generator/ Starting Clutch
Start motor
If the crankshaft bearing or timing sprocket need be replaced, then the crankshaft set
have to replaced.
Specification
Left, right clearance of the big end of the connecting rod
Radial clearance of the big end of the connecting rod
Run-out
Torque value
Bolts for crankcase
Cylinder/cylinder head two ends bolts
Engine oil draining plug bolt
Pivot for cam chain tensioner
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
• Loose crankshaft bearing
• Loose crankshaft pin bearing
• Wear piston pin or piston pin hole
11-2
Item
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 10
Chapter 16
Standard
0.100~0.350
0.000~0.008
─
1.5~2.0 kgf-m
0.8~1.2 kgf-m
3.5~4.5 kgf-m
0.8~1.2 kgf-m(Hex socket bolt)
SYM
Unit: mm
Limit
0.550
0.050
Below 0.030