Daedong DSC48 - Servicing

2
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Apr. 2007
DSC48
417W275A
417W276A
3.3.5 SERVICING
A. CYLINDER HEAD AND VALVE
► CYLINDER HEAD SURFACE FLATNESS
1. Thoroughly clean the cylinder head surface.
2. Place a straightedge on the cylinder head and measure
the clearance with a feeler gage as shown in the fi gure.
3. If the measurement exceeds the allowable limit, replace
the cylinder head.
• Do not place an straightedge on the combustion
camber.
IMPORTANT
► CYLINDER HEAD SURFACE FLAW
1. Prepare an air spray red check.
2. Clean the cylinder head surface with the detergent (B).
3. Spray the cylinder head surface with the red perme-
ative liquid (A).
4. Wash away the red permeative liquid on the cylinder
head surface with the detergent (B) after ten minutes.
5. Spray the white developer (C) on the cylinder head sur-
face.
6. If any fl aw is found such as a red mark, replace the cyl-
inder head.
► VALVE STEM AND GUIDE CLEARANCE
1. Remove the carbon from the valve guide.
2. Measure the valve stem O.D. with an outside microm-
eter.
3. Measure the valve guide I.D. with the cylinder gauge
and calculate the clearance.
4. If the measurement exceeds the allowable limit, re-
place the valve or valve guide.
417W277A
Factory spec. Allowable limit
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0.05 mm
0.002 in.
Factory spec. Allowable limit
Valve stem
clearance
0.040 ~ 0.070 mm
0.002 ~ 0.003 in.
0.1 mm
0.004 in.
Valve guide
bore I.D.
8.015 ~ 8.030 mm
0.316 ~ 0.316 in.
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Valve stem
O.D.
7.960 ~ 7.975 mm
0.313 ~ 0.314 in.
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