5. CYLINDER HEAD/CYLINDER/PISTON
5-2
Maintenance Information
Precautions in Operation
y The inspection and maintenance of the cylinder head, cylinder and piston can be carried as engine
mounted on the body.
y It should clean the engine to prevent dirt from entering into cylinder and crankcase before removal.
y Remove all washes from the interfaces of cylinder head, cylinder and crankcase.
y Be careful do not damage cylinder head, cylinder and piston when removing.
y Inspect the removed & cleaned parts thoroughly, and apply with oil onto the rotation surfaces before
installation.
Specification
FA05 series
Item
Standard value (mm) Limit (mm)
Cylinder head Deformation - 0.100
Piston OD 39.030~39.045 38.935
Clearance between cylinder and piston 0.040~0.050 0.100
Piston pin hole 12.002~12.008 12.030
Piston pin OD 11.994~12.000 11.970
Clearance between piston and piston pin 0.002~0.014 0.030
Piston ring end gap 0.100~0.250 0.400
Piston
ID of connecting rod small end 17.05~17.015 17.025
ID 39.000~39.015 39.050
Cylinder
Deformation - 0.100
ID: inner diameter
OD: outer diameter
Tighten torque value
Cylinder head 1.0kgf-m
Spark plug 1.4kgf-m
Exhaust pipe connection nut 1.2kgf-m
Exhaust muffler mounting bolt 3.3kgf-m
Troubleshooting
Compression Pressure Too Low/Difficult
To Start/Rough Idling
1. Cylinder head gasket leaking
2. Spark plug not tighten enough
3. Worn, seized or crack piston ring
4. Damaged, worn cylinder or piston
5. Poor reed
Compression Pressure Too
High/Overheat/Knock
1. Too much carbon deposit built up in
combustion chamber
Piston Noise
1. cylinder and piston worn out
2. piston pin or piston pin hole worn out
3. connecting rod small end bearing worn out
Piston Ring Noise
1. Worn, seized or crack piston ring
2. Cylinder worn out or damaged
This chapter Contents
To Next Page
Loading...
Need help?
General
