Cylinder Specifications; Cylinder Troubleshooting; Knock Or Noise; Smoking In Exhaust Pipe - Eton VECTOR ST 250 Service Manual

7-2 Precautions in Operation
General Information
Both cylinder and piston service cannot be carried out when engine mounted on frame.
Specification of CYLINDER
ID
Cylinder
Bend
Clearance between piston
rings
Ring-end gap
Piston/
Piston ring
OD of piston (2
Clearance between piston and cylinder
ID of piston pin boss
OD of piston pin
Clearance between piston and piston pin
ID of connecting rod small-end
7-3 Trouble Diagnosis
Low or Unstable Compression Pressure
Cylinder or piston ring worn out

Knock or Noise

Cylinder or piston ring worn out
Carbon deposits on cylinder head top-side
Piston pin hole and piston pin wear out
Item
Top ring
nd
2 ring
Top ring
nd
2 ring
Oil ring side rail
nd
)
Standard
70.995~71.015
0.015~0.050
0.015~0.050
0.150~0.300
0.300~0.450
0.200~0.700
70.430~70.480
0.010~0.040
17.002~17.008
16.994~17.000
0.002~0.014
17.016~17.034

Smoking in Exhaust Pipe

Piston or piston ring worn out
Piston ring installation improperly
Cylinder or piston damage
Engine Overheat
Carbon deposits on cylinder head top side
Cooling pipe clogged or not enough in coolant
flow
51
Limit
71.100
- 0.050
0.090
0.090
0.500
0.650
70.380
0.100
16.970
16.960
0.020
17.064
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