4 - 9
ENG
CYLINDER HEAD
EBS00230
CHECKING THE CYLINDER HEAD
1. Eliminate:
• combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
_
Do not use a sharp instrument to avoid damag-
ing or scratching:
• spark plug bore threads
• valve seats
2. Check:
• cylinder head
Damage/scratches
→
Replace.
• cylinder head water jacket
Mineral deposits/rust
→
Eliminate.
3. Measure:
• cylinder head warpage
Out of specification
→
Resurface the cylin-
der head.
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a. Place a straightedge and a thickness gauge
across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylin-
der head as follows.
d. Place a 400 ~ 600 grit wet sandpaper on
the surface plate and resurface the cylinder
head using a figure-eight sanding pattern.
NOTE:
_
To ensure an even surface, rotate the cylinder
head several times.
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Maximum cylinder head warpage
0.05 mm (0.002 in)
Summary of Contents for 5YF2-AE1
Page 1: ...YFM50S5YF2 AE1 SERVICE MANUAL ...
Page 2: ......
Page 8: ......
Page 9: ...GEN INFO 1 ...
Page 11: ...GEN INFO ...
Page 20: ...SPEC 2 ...
Page 22: ...SPEC ...
Page 44: ...2 22 SPEC OIL FLOW DIAGRAMS 1 Oil pump 2 Oil strainer ...
Page 53: ...CHK ADJ 3 ...
Page 55: ...CHK ADJ ...
Page 94: ...ENG 4 ...
Page 163: ...CARB 5 ...
Page 165: ...CARB ...
Page 172: ...DRIV 6 ...
Page 174: ...DRIV ...
Page 188: ......
Page 189: ...CHAS 7 ...
Page 220: ...ELEC 8 ...
Page 222: ... ELEC ...
Page 250: ......
Page 251: ...TRBL SHTG 9 ...
Page 253: ...TRBL SHTG ...
Page 259: ......
Page 260: ......
Page 261: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN ...