CHECKING THE VALVES AND VALVE
SPRINGS
1. Measure:
• Stem-to-guide clearance
• Out of specification → Replace the cylinder
head ass'y.
Stem-to-guide clearance =
valve guide inside diameter
–
valve stem diameter
Stem-to-guide clearance
Intake
0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)
<Limit>: 0.08 mm (0.0031 in)
Exhaust
0.030 ~ 0.057 mm
(0.0012 ~ 0.0022 in)
<Limit>: 0.10 mm (0.0039 in)
a
a
b
a
b
a
2. Check:
• valve face
Pitting/wear → Grind the face.
• valve stem end
Mushroom shape or diameter larger than
the body of the stem → Replace.
3. Measure:
• margin thickness
Out of specification → Replace.
Margin thickness
Intake
0.55 ~ 0.85 mm
(0.0217 ~ 0.0335 in)
Exhaust
0.95 ~ 1.25 mm
(0.0374 ~ 0.0492 in)
4. Measure:
• runout (valve stem)
Out of specification → Replace.
Runout limit
0.02 mm (0.0008 in)
CAMSHAFT, ROCKER ARMS AND VALVES
ENG
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