General Information; Trouble Diagnosis - Sym HD 125 Service Manual

11. CRANKCASE / CRANK

General information

Operational precautions
This Section concerns disassembly of the crankcase for repair purpose.
Remove following components before disassembling crankcase.
¡ Ð Engine
¡ Ð Cylinder head
¡ Ð Cylinder and piston
¡ Ð Drive pulley and driven pulley
¡ Ð AC generator/Start driven gear
¡ Ð Starting motor
In case it requires replacing the crankshaft bearing, the driving chain of engine oil pump or the timing
chain, it is preferably to replace crankshaft as a unit.
Specification
Connecting rod side clearance of the big end
Crankshaft
Vertical clearance of the big end of the connecting rod
Run-out
Torque value
Bolts for crankcase
Bolts for cam chain adjuster
Tools
Special tools
R/L. crank disassemble/ install tool: SYM-1300001-H9A
L. crank shaft bearing driver: SYM-9100200-H9A
Crank shaft bearing fixing socket: SYM-9100210-H9A
Crank shaft puller: SYM-1130000-H9A
L. crank shaft oil seal driver (25*40*8): SYM-9121600
Outer bearing puller: SYM-6204010
Inner bearing puller: SYM-6204020
Clutch nut wrench: SYM-9020200

Trouble diagnosis

Engine noise
Loose crankshaft bearing
Loose crankshaft pin bearing
Worn out piston pin and pin hole
11-2
To this chapter contents
Section 5
Section 6
Section 7
Section 8
Section 10
Section 16
Item
0.8~1.2kgf-m
1.2~1.6kgf-m
Unit: mm
Standard Limit
0.100~0.400 0.600
0~0.008 0.050
- 0.100