Yamaha YZ250 2022, Owner'S Service Manual

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CYLINDER HEAD, CYLINDER AND PISTON
5-14
•
Push rod bolt “2”
NOTICE
ECA27140
Be sure to use the set pin. If the set pin is not
used, the power valve constituent parts will
result in damage.
TIP
• Insert the set pin “3” included in owner’s tool kit
to install the push rod bolt.
• Do not forget to remove the set pin.
7. Remove:
• Set pin
8. Install:
• Gasket (power valve housing)
•
Power valve housing “1”
•
Power valve housing bolt “2”
EAM30555
INSTALLING THE CYLINDER HEAD
1. Lubricate:
• O-ring
2. Install:
• O-ring “1”
•
Dowel pin “2”
TIP
Apply the lithium-soap-based grease on the O-
rings.
3. Install:
•
Cylinder head “1”
•
Copper washer “2”
• Cylinder head nut “3”
TIP
Tighten the cylinder head nut in stage, using a
crisscross pattern.
4. Install:
•
Spark plug
• Spark plug cap
•
Radiator hose
Push rod bolt
4.5 N·m (0.45 kgf·m, 3.3 lb·ft)
Power valve housing bolt
4.5 N·m (0.45 kgf·m, 3.3 lb·ft)
Recommended lubricant
Lithium-soap-based grease
T
R
.
.
Ne w
T
R
.
.
Cylinder head nut
25 N·m (2.5 kgf·m, 18 lb·ft)
Spark plug
20 N·m (2.0 kgf·m, 15 lb·ft)
Ne w
1
2
2
New
T
R
.
.
T
R
.
.