Yamaha YZ250 User Manual

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IMPORTANT INFORMATION
GEN
INFO
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings should be
replaced when an engine is overhauled. All
gasket surfaces, oil seal lips, and O-rings
must be cleaned.
2. Properly oil all mating parts and bearings
during reassembly. Apply grease to the oil
seal lips.
EC134000
LOCK WASHERS/PLATES AND COTTER
PINS
1. All lock washers/plates 1 and cotter pins
must be replaced when they are removed.
Lock tab(s) should be bent along the bolt or
nut flat(s) after the bolt or nut has been
properly tightened.
EC135001
BEARINGS AND OIL SEALS
1. Install the bearing (s) 1 and oil seal (s) 2
with their manufacturer’s marks or numbers
facing outward. (In other words, the
stamped letters must be on the side
exposed to view.) When installing oil seal(s),
apply a light coating of light-weight lithium
base grease to the seal lip(s). Oil the bear-
ings liberally when installing.
cC
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.
EC132000
ALL REPLACEMENT PARTS
1. We recommend to use Yamaha genuine
parts for all replacements. Use oil and/or
grease recommended by Yamaha for
assembly and adjustment.
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Yamaha YZ250 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
Brakes Rear	Hydraulic disc, 240mm
Tires Front	80/100-21
Tires Rear	110/90-19
Length	85.8 in
Width	32.5 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
Fuel Delivery	Keihin PWK38S carburetor