VALVES AND VALVE SPRINGS
5-23
EAM30090
REMOVING THE VALVES
TIP
Before removing the internal parts of the cylinder
head (e.g., valves, valve springs, valve seats),
make sure that the valves are properly sealed.
1. Remove:
•
Valve lifter “1”
•
Adjusting pad “2”
TIP
•
Place a cloth in the timing chain space to pre-
vent adjusting pads from falling into the crank-
case.
•
Make a note of the positions of valve lifters and
adjusting pads so that they can be reinstalled
in their original places.
2. Check:
•
Valve sealing
Leakage at the valve seat
Check the valve
face, the valve seat, and the valve seat con-
tact width.
Refer to “CHECKING THE VALVE SEATS”
on page 5-25.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Pour a clean solvent “a” into the intake and
exhaust ports.
b. Check that the valves are properly sealed.
TIP
Check that there are no kerosene leaks from the
valve seat “1”.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
3. Remove:
•
Valve cotter “1”
TIP
Remove the valve cotters by compressing the
valve spring with the valve spring compressor
“2” and the valve spring compressor attachment
“3”.
4. Remove:
•
Valve spring retainer “1”
•
Valve spring “2”
•
Valve “3”
•
Valve stem seal “4”
•
Valve spring seat “5”
TIP
Identify the position of each part very carefully so
Valve lapper (ø14)
90890-04101
Valve lapping tool (14mm)
YM-A8998
1
2
Valve spring compressor
90890-04019
Valve spring compressor
YM-04019
Valve spring compressor attach-
ment
90890-04108
Valve spring compressor adapter
22 mm
YM-04108
a
1
a
Summary of Contents for YZ 2019 Series
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 40: ...MOTORCYCLE CARE AND STORAGE 1 28...
Page 63: ...LUBRICATION POINTS AND LUBRICANT TYPES 2 22...
Page 66: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25...
Page 68: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27...
Page 70: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 29...
Page 72: ...CABLE ROUTING DIAGRAM 2 31 EAM20152 CABLE ROUTING DIAGRAM...
Page 74: ...CABLE ROUTING DIAGRAM 2 33...
Page 76: ...CABLE ROUTING DIAGRAM 2 35...
Page 78: ...CABLE ROUTING DIAGRAM 2 37...
Page 80: ...CABLE ROUTING DIAGRAM 2 39...
Page 82: ...CABLE ROUTING DIAGRAM 2 41...
Page 84: ...CABLE ROUTING DIAGRAM 2 43...
Page 86: ...CABLE ROUTING DIAGRAM 2 45...
Page 126: ...ELECTRICAL SYSTEM 3 38...
Page 177: ...FRONT FORK 4 49 1...
Page 196: ...CHAIN DRIVE 4 68...
Page 217: ...CAMSHAFT 5 18 Spark plug Spark plug 13 N m 1 3 kgf m 9 6 lb ft T R...
Page 237: ...ELECTRIC STARTER 5 38...
Page 256: ...OIL PUMP AND BALANCER GEAR 5 57 a 2 10 b 2 9 1 b 5 3 a 4 10 5 9 3 E c d 6 7 8 8 b 6...
Page 262: ...GENERATOR AND STARTER CLUTCH 5 63 1 a 3 3 2 4...
Page 276: ...TRANSMISSION 5 77...
Page 284: ...WATER PUMP 6 7...
Page 290: ...FUEL TANK 7 5 A Left B Right 1 1 A 0 mm 0 in B 1 1 15 mm 0 59 in...
Page 296: ...THROTTLE BODY 7 11...
Page 299: ......
Page 313: ...CHARGING SYSTEM 8 14...
Page 343: ...FUEL INJECTION SYSTEM 8 44...
Page 347: ...FUEL PUMP SYSTEM 8 48...
Page 348: ...ELECTRICAL COMPONENTS 8 49 EAM20147 ELECTRICAL COMPONENTS 9 10 1 3 2 4 5 6 7 8...
Page 350: ...ELECTRICAL COMPONENTS 8 51 11 10 9 2 3 1 6 7 8 4 5...
Page 352: ...ELECTRICAL COMPONENTS 8 53 EAM30289 CHECKING THE SWITCHES 4 1 3 2 B B Sb B B B B B B B B...
Page 368: ...ELECTRICAL COMPONENTS 8 69...
Page 376: ...LIST OF SELF DIAGNOSTIC AND FAIL SAFE ACTIONS 9 7...