DAELIM NS125DLX, Service Manual

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Cylinder/Piston
10-1
10. Cylinder/Piston
Services information 10-1
Troubleshooting 10-1
Cylinder 10-2
Piston 10-3
Piston/Cylinder assembly 10-5
Service Information
General Safety
●
Take precautions not to damage the joint part with a driver when removing the cylinder, or not to damage
the cooling pin by striking the cylinder too hard.
●
Take precautions not to damage the inside of the cylinder or the exterior part of the piston.
●
Check parts after disassembling, and clean and dry with an air hose prior to taking measurements.
Troubleshooting
Compression low
●
Worn cylinder or piston rings
●
Leaking valve seats
Excessive smoke
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Worn cylinder or piston
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Improper installation of piston rings
●
Scored or scratched piston or cylinder wall
Overheating
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Excessive carbon build-up on the piston
combustion
●
Incorrect spark plug
Knocking or abnormal noise
●
Worn piston and cylinder
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Excessive carbon build-up
●
Low octane fuel
Item Standard value Service limit
Inner diameter 56.000-56.010(2.2047-2.2051) 56.100(2.2087)
Cylinder
Cylindricality
───
0.050(0.002)
Out of roundness
───
0.005(0.0002)
Head contact warpage
───
0.020(0.0008)
Piston skirt outer diameter 55.925-55.945(2.2018-2.2026) 54.832(2.1587)
Piston pin hole inner diameter 15.002-15.008(0.5906-0.5909) 15.038(0.5920)
Piston pin outer diameter 14.994-15.000(0.5903-0.5906) 14.960(0.5890)
Piston,
Piston-to-piston pin clearance 0.002-0.140(0.0001-0.0006) 0.020(0.0008)
Piston pin,
Piston ring-to groove Top 0.040-0.057(0.0016-0.0026) 0.110(0.0043)
Piston ring
clearance Second 0.025-0.052(0.0010-0.020) 0.080(0.0031)
Piston ring Top/second 0.10-0.25(0.004-0.010) 0.50(0.020)
joint gap Oil(side rail) 0.20-0.70(0.008-0.028) 1.10(0.040)
Cylinder-to piston clearance 0.055-0.085(0.0022-0.0033) 0.340(0.0134)
Connecting rod small end inner diameter 15.010-15.028(0.5909-0.5917) 15.060(0.5930)
Gap between connecting rod small end and piston pin 0.010-0.034(0.004-0.0013) 0.040(0.0020)
Specifications
Unit: mm(in)
10