Yamaha MX250 - Page 40

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ENGINE
ENGINE INSPECTION
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Testing step (above the maximum specification):
a. Check the cylinder head, valve surfaces, and piston
crown for carbon deposits.
Carbon deposits  Eliminate.
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5.
Install:
• Spark plug
• Spark plug cap
Reading Diagnosis
Higher than
without oil
• Worn cylinder, piston, and piston ring(s)
Same as
without oil
• Defective piston, piston ring(s), valve(s), and
cylinder head gasket
• Improper valve timing and valve clearance
Spark plug:
20 N·m (2.0 kgf·m, 15 lb·ft)
T
R
.
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