ENG
CYLINDER HEAD
CHECKING THE CYLINDER HEAD
1. Dispose:
• combustion chambers carbon deposits (with
a round scraper)
Do not use a sharpen tool, to prevent damage or
scratches in:
• spark plug threads
• valve seats
NOTE:
2. Check:
• cylinder head
Damage/Scratches
-->
Replace.
3. Measure:
• cylinder head runout
Out of specification
-->
Remove the cylinder
head.
Maximum runout
0.03 mm (0.001 in)
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a. Place a ruler
1
and a thickness gauge
2
along the cylinder head.
b. Measure the runout.
c. When the limit is exceed, rebore the cylinder.
d. With a thin sandpaper (400 to 600 grainy) is
applied to the cylinder head surface, carry out
the grinding, making movements following the
“8” shape.
To ensure a level surface, spin the cylinder head
several times.
NOTE:
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5-10
Summary of Contents for YBR250 2007
Page 1: ...YBR250 SERVICE MANUAL 5D1 F8197 E0 2007 ...
Page 2: ......
Page 359: ...YAMAHA MOTOR DA AMAZÔNIA LTDA ...
