Installing The Cylinder Head - Yamaha YZ250 2022 Owner's Service Manual

• Push rod bolt "2"
Push rod bolt
4.5 N·m (0.45 kgf·m, 3.3 lb·ft)
ECA27140
NOTICE
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"
Power valve housing bolt
4.5 N·m (0.45 kgf·m, 3.3 lb·ft)
EAM30555

INSTALLING THE CYLINDER HEAD

1. Lubricate:
• O-ring
Recommended lubricant
Lithium-soap-based grease
CYLINDER HEAD, CYLINDER AND PISTON
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.
New
4. Install:
• Spark plug
• Spark plug cap
• Radiator hose
5-14
New
2
1
2
New
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)