Yamaha YZ250 2021 User Manual

ENGINE
3-9
7. Apply:
• Lithium soap base grease
(on the matching surface “a” on air filter ele-
ment)
8. Install:
• Air filter element “1”
• Washer
• Fitting bolt
TIP
Align the projection “a” on filter guide with the
hole “b” in air filter case.
NOTICE
ECA26420
Make sure that the air filter element is prop-
erly seated in the air filter case. The engine
should never be operated without the air fil-
ter element installed, otherwise the piston(s)
and/or cylinder(s) may become excessively
worn.
EAM30541
CHECKING THE CARBURETOR JOINT
1. Check:
• Carburetor joint “1”
Cracks/damage  Replace.
EAM30542
CHECKING THE CARBURETOR HOSES
The following procedure applies to all of the fuel
and vacuum hoses.
1. Check:
• Fuel hose
• Carburetor breather hose “1”
• Overflow hose “2”
Cracks/damage  Replace.
Loose connection  Connect properly.
EAM30221
CHECKING THE EXHAUST SYSTEM
1. Remove:
• Exhaust pipe
• Silencer
2. Check:
• Exhaust pipe
• Silencer
Crack/damage  Replace.
3. Check:
• Silencer fiber
Damage  Replace.
4. Replace:
• Silencer fiber
a. Remove the silencer bolts “1”, silencer “2”
and fiber bolts “3”.
Fitting bolt
2.0 N·m (0.20 kgf·m, 1.5 lb·ft)
a
T
R
.
.
1
1
2
1

Yamaha YZ250 2021 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
Width	32.5 in
Height	50.8 in
Wheelbase	58.5 in
Ground Clearance	14.2 in
Fuel Capacity	2.1 gal
Wet Weight	227 lb
Fuel Delivery	Keihin PWK38S carburetor
Suspension Front	KYB® Speed-Sensitive System inverted fork; fully adjustable, 11.8-in travel
Brakes Rear	Hydraulic disc, 245mm