Yamaha YZ250 2022 User Manual

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
.
.
New
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)
New
1
2
2
New
T
R
.
.
T
R
.
.

Yamaha YZ250 2022 Specifications

General

Engine Type	249cc liquid-cooled 2-stroke; reed-valve inducted
Bore x Stroke	66.4mm x 72.0mm
Compression Ratio	8.9~10.6:1
Ignition	CDI
Transmission	5-speed; multiplate wet clutch
Final Drive	Chain
Suspension Rear	KYB® single shock; fully adjustable, 12.4-in travel
Brakes Front	Hydraulic disc, 270mm
Tires Front	80/100-21
Tires Rear	110/90-19
Seat Height	38.2 in
Wheelbase	58.5 in
Ground Clearance	14.2 in
Fuel Capacity	2.1 gal
Wet Weight	227 lb
Suspension Front	KYB® inverted fork; fully adjustable, 11.8-in travel
Brakes Rear	Hydraulic disc, 245mm