VALVES AND VALVE SPRINGS
5-26
3. Eliminate:
•
Carbon deposits
(from the valve face and valve seat)
4. Check:
•
Valve face
Pitting/wear
Grind the valve face.
•
Valve stem end
Mushroom shape or diameter larger than the
body of the valve stem
Replace the valve.
5. Measure:
•
Valve stem runout
Out of specification
Replace the valve.
TIP
•
When installing a new valve, always replace
the valve guide.
•
If the valve is removed or replaced, always re-
place the valve stem seal.
EAM30092
CHECKING THE VALVE SEATS
1. Eliminate:
•
Carbon deposits
(from the valve face and valve seat)
2. Check:
•
Valve seat
Pitting/wear
Replace the cylinder head.
3. Measure:
•
Valve seat contact width “a”
Out of specification
Replace the cylinder
head.
a. Apply blue layout fluid “b” onto the valve
face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide
and onto the valve seat to make a clear
impression.
d. Measure the valve seat contact width “c”.
TIP
Where the valve seat and the valve face are in
contact with each other, the blueing will have
been removed.
Valve guide remover & installer
set (ø5.5)
90890-04016
Valve guide remover (5.5 mm)
YM-01122
Valve guide installer (ø5.5)
90890-04015
Valve guide installer (5.5 mm)
YM-04015
Valve guide reamer (5.5 mm)
90890-01196
Valve guide reamer (5.5 mm)
YM-01196
Valve stem runout
0.020 mm (0.0008 in)
Valve seat contact width limit (in-
take)
1.5 mm (0.06 in)
Valve seat contact width limit (ex-
haust)
1.5 mm (0.06 in)
c
c
c
Summary of Contents for YZ450FP 2023
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 44: ...MOTORCYCLE CARE AND STORAGE 1 32...
Page 61: ...TIGHTENING TORQUES 2 16...
Page 72: ...CABLE ROUTING DIAGRAM 2 27 Frame and battery top view 2 1 B 5 4 3 A 7 4 E 6 D 2 3 C...
Page 76: ...CABLE ROUTING DIAGRAM 2 31...
Page 154: ...REAR BRAKE 4 38 system Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM on page 3 26...
Page 194: ...CHAIN DRIVE 4 78...
Page 278: ...TRANSMISSION 5 82...
Page 300: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM...
Page 305: ...IGNITION SYSTEM 8 6...
Page 306: ...ELECTRIC STARTING SYSTEM 8 7 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM...
Page 310: ...CHARGING SYSTEM 8 11 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM...
Page 313: ...CHARGING SYSTEM 8 14...
Page 314: ...FUEL INJECTION SYSTEM 8 15 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM B...
Page 339: ...FUEL INJECTION SYSTEM 8 40...
Page 340: ...FUEL PUMP SYSTEM 8 41 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM...
Page 356: ...ELECTRICAL COMPONENTS 8 57...
Page 372: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15...
Page 382: ...CHASSIS 10 9...
Page 384: ......
Page 386: ......
Page 387: ...B YZ450FP 2023 WIRING DIAGRAM BHR 2819U 10_W D indd 1 2022 08 09 13 16 06...