4 - 18
ENG
CAMSHAFT, ROCKER ARMS AND VALVES
3. Check:
• valve face
Pitting/wear
→
Grind the face.
• valve stem end
Mushroom shape or diameter larger than
the body of the stem
→
Replace.
4. Measure:
• margin thickness
a
Out of specification
→
Replace.
Margin thickness
Intake
0.5 ~ 0.9 mm
(0.0197 ~ 0.0354 in)
<Limit>: 1.6 mm (0.0630 in)
Exhaust
0.6 ~ 1.0 mm
(0.0236 ~ 0.0394 in)
<Limit>: 1.6 mm (0.0630 in)
5. Measure:
• runout (valve stem)
Out of specification
→
Replace.
NOTE:
_
• When installing a new valve always replace
the guide.
• If the valve is removed or replaced always
replace the oil seal.
6. Eliminate:
• carbon deposits
(from the valve face and valve seat)
7. Check:
• valve seats
Pitting/wear
→
Reface the valve seat.
Runout limit
0.02 mm (0.0008 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 ...