Yamaha AEROX YQ50, Service Manual

Page: 72 / 192

ENG
4-11
307003
301002
INSPECTION AND REPAIR
INSPECTION AND REPAIR
CYLINDER HEAD
1. Eliminate :
• Carbon deposits
Use a rounded scraper
Q
NOTE:
Take care to avoid damaging the spark plug
threads. Do not use a sharp instrument. Avoid
scratching the aluminum.
2. Inspect :
• Cylinder head warpage
Out of specification
➞
Re-surface.
*******************************************************
Warpage measurement and re-surfacement
steps :
●
Attach a straight edge
Q
and a thickness
gauge W to the cylinder head.
●
Measure the warpage limit.
Warpage limit :
0.02 mm (0.0078 in)
●
If the warpage is out of specification, re-surface
the cylinder head.
NOTE:
Rotate the head several times to avoid removing
too much material from one side.
*******************************************************
CYLINDER AND PISTON
1. Eliminate :
• Carbon deposits
Use a rounded scraper
Q
2. Inspect :
• Cylinder wall
Wear/Scratches
➞
Replace.
3. Eliminate :
• Carbon deposits
From the piston crown
Q
and ring grooves
W
.
4. Remove :
• Score marks and lacquer deposits
From the sides of piston.
NOTE:
Sand in a crisscross pattern. Do not sand
excessively.
301003
304001