Cylinder And Piston Operation Notice; Cylinder And Piston Data - PGO G-MAX 50 Service Manual

A.Troubleshooting.
a.Compression pressure is too low, difficult to start engine and engine running
unsmoothly.
1.Cylinder head gasket cracked
2.Spark plug is not well locked
3.Piston ring worn out or cracked
4.Cylinder, piston worn out.
5.Reed valve is out of order.
b.Compression pressure is too high; Engine overheating; abnormal noise.
1.piston tip has too much carbon accumulated.
c.Abnormal piston noise
1.Cylinder and piston worn out.
2.Piston pin hole or Piston pin worn out.
3.Connecting rod small end or bearing worn out.
d.Abnormal piston or cylinder noise
1.Piston ring worn out or cracked
2.Cylinder worn out or cracked
B.The operation notice
1.Clean before operation to avoid particles dropping into the engine.
2.The contact surface of gasket must be clean.
3.Dismantle cylinder and cylinder head by screw driver. Do not injure the contact surface.
4.Cylinder inner surface and piston outer face can't be injured. Contact
Surface should lubricate by specified oil.
C.Data (125CC)
Part name /description
Bore
Curve
Cylinder
Cylindrility
Roundness
Clearance b/w Piston and
Piston ring
Clearance of cutting
section
Piston/
Piston ring
Piston outer diameter
Measuring location of piston outer dia.
Clearance b/w piston and cylinder
Piston pin hole inner dia
Piston pin outer diameter
Clearance between piston and piston pin
Connecting rod small end inner dia
Standard value
51.490~51.510
lst ring
nd
2 ring
lst ring
nd
2 ring
side ring
51.460~51.480
Down to 7mm from the
piston skirt
13.022~13.013
12.996~13.00
13.015~13.028
( mm )
-
-
-
0.03~0.07
0.02~0.06
0.15~0.35
0.15~0.35
0.2~0.8
0.025~0.035
0.02~0.017
Limit of use
( mm )
51.60
0.005
0.005
0.005
0.10
0.10
0.50
0.50
-
51.40
-
0.10
13.045
12.96
0.025
13.060