Sym DD 50 Service Manual

9. CRANKCASE/CRANKSHAFT
9-2
Maintenance Information
y This chapter concerns disassembly of the crankcase for repair purpose.
y Before disassembling crankcase, except removing engine firstly, following components must be
removed too.
• Carburetor (chapter 10)
• Oil pump (chapter 3)
• Reed valve (chapter 10)
• Driving belt (chapter 7)
• Alternator (chapter 6)
• Cylinder head/cylinder/piston (chapter 5)
y Except above components are needed be removed, when disassembling L crankcase, following
components must be removed too.
• Final driving mechanism (chapter 8)
y When assembling both crankcase and crankshaft, it has press the inner ring edge of the crankshaft
bearing to push the crankshaft into the crankcase hole by using the specified service tools. The old
bearing onto the crankshaft has to be removed. Then install a new bearing onto the crankshaft on
the crankcase side. Oil seal has to be replaced with new one after assembled the crankcase.
Item Standard Limit (mm)
Lateral clearance of the big end of the connecting rod
─
0.60
Radial clearance of the big end of the connecting rod
─
0.04
Crankshaft run-out point A
─
0.10
Crankshaft run-out point B
─
0.10
Special Tools
Crankcase disassemble tool (SYM-1120100-G5)
Outer bearing puller (SYM-6204010)
R. Crank shaft puller (SYM-1130000-R)
R. Crank shaft install bush (SYM-1130020)
L. Crank shaft puller (SYM-1130000-L)
L. Crank shaft install bush (SYM-1130010)
20*32*6 Oil seal driver (SYM-9120200)
Bearing driver 6204 (SYM-9110400)
Troubleshooting
Engine noise
1. Worn bearing of connecting rod bog end
2. Bend connecting rod
3. Worn crankshaft bearing
This chapter Contents

Sym DD 50 Specifications

General

Brand	Sym
Model	DD 50
Category	Scooter
Language	English