Piston Pin And Piston Removal; Cylinder Head Inspection - Yamaha YW50AP Service Manual

CYLINDER HEAD, CYLINDER, PISTON
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2
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PISTON PIN AND PISTON REMOVAL

1. Remove:
8 Piston pin clip 1
NOTE:
Before removing the piston pin clip, cover the
crankcase with a clean rag so you will not acci-
dentally drop the clip into the crankcase.
2. Remove:
8 Piston pin 1
8 Piston 2
8 Piston pin bearing 3
cC
Do not use a hammer to drive the piston pin
out.

CYLINDER HEAD INSPECTION

1. Eliminate:
8 Carbon deposits
Use a rounded scrapper 1.
2. Inspect:
8 Cylinder head warpage
Out of specification→Re-surface.
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Warpage measurement and re-surfacement
steps:
8 Attach a straight edge 1 and a thickness
gauge 2 on the cylinder head.
8 Measure the warpage limit.
Warpage limit:
0.03 mm(0.0012 in)
8 If the warpage is out of specification, reface
the cylinder head.
NOTE:
Rotate the head severai tires to avoid remov-
ing too much material from one side.
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ENG