weight YAMAHA WR 250F 2001 Manuale duso (in Italian)

EC050000
TO THE NEW OWNER
This manual will provide you with a good basic
understanding of features, operation, and
basic maintenance and inspection items of this
machine. Please read this manual carefully
and completely before operating your new
machine. If you have any questions regarding
the operation or maintenance of your machine,
please consult your Yamaha dealer.
NOTE:

This manual should be considered a perma-
nent part of this machine and should remain
with it even if the machine is subsequently
sold.
EC060000
NOTICE
Some data in this manual may become out-
dated due to improvements made to this
model in the future. If there is any question
you have regarding this manual or your
machine, please consult your Yamaha
dealer.
EC070001
F.I.M. MACHINE WEIGHTS:
Weights of machines without fuel
The minimum weights for motocross
machines are:
for the class 125 cc....................... minimum
88 kg (194 lb)
for the class 250 cc....................... minimum
98 kg (216 lb)
for the class 500 cc....................... minimum
102 kg (225 lb)
In modifying your machine (e.g., for weight
reduction), take note of the above limits of
weight.

ILLUSTRATED SYMBOLS
(Refer to the illustration)
Illustrated symbols
1
to
7
are designed as
thumb tabs to indicate the chapter’s number
and content.
1
General information
2
Specifications
3
Regular inspection and adjustments
4
Engine
5
Chassis
6
Electrical
7
Tuning
Illustrated symbols
8
to
D
are used to identify
the specifications appearing in the text.
8
With engine mounted
9
Special tool
0
Filling fluid
A
Lubricant
B
Tightening
C
Specified value, Service limit
D
Resistance (
W
), Voltage (V), Electric current (A)
Illustrated symbols
E
to
H
in the exploded
diagrams indicate grade of lubricant and loca-
tion of lubrication point.
E
Apply engine oil
F
Apply molybdenum disulfide oil
G
Apply lightweight lithium-soap base grease
H
Apply molybdenum disulfide grease
Illustrated symbols
I
to
J
in the exploded
diagrams indicate where to apply a locking
agent and where to install new parts.
IApply locking agent (LOCTITE
®)
JUse new one 12
34
56
78
90
AB
CD
EF
GH
IJ
GEN
INFOSPEC
INSP
ADJENG
CHAS–+ELEC
TUN
T R..
EM
BM

1 - 4
GEN
INFO

IMPORTANT INFORMATION
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.
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings should
be replaced when an engine is over-
hauled. 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 num-
bers 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 bearings liberally when
installing.
CAUTION:
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.

SPEC

2 - 1
GENERAL SPECIFICATIONS
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: WR250FN (USA)
WR250F (EUROPE)
WR250F(N) (CDN, AUS, NZ, ZA)
Model code number: 5PH1 (USA)
5PH2 (EUROPE)
5PH4 (CDN, AUS, NZ, ZA)
Dimensions:
Overall length 2,165 mm (85.2 in)
Overall width 827 mm (32.6 in)
Overall height 1,303 mm (51.3 in)
Seat height 998 mm (39.3 in)
Wheelbase 1,475 mm (58.1 in)
Minimum ground clearance 382 mm (15.0 in)
Basic weight:
With oil and full fuel tank 110.0 kg (242.5 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 249 cm
3

(8.76 Imp oz, 8.42 US oz)
Bore

´

stroke 77.0
´
53.6 mm (3.03
´
2.11 in)
Compression ratio 12.5 : 1
Starting system Kickstarter
Lubrication system: Dry sump
Oil type or grade:
Engine oil (For USA and CDN)
At 5 ˚C (40 ˚F) or higher

Yamalube 4 (20W-40) or SAE 20W-40 type
SH motor oil
(Non-Friction modified)
At 15 ˚C (60 ˚F) or lower
õ

Yamalube 4 (10W-30) or SAE 10W-30 type
SH motor oil
(Non-Friction modified)
and/or
Yamalube 4-R (15W-50)
(Non-Friction modified)
(Except for USA and CDN)
API “SH” or higher grade
-20
-4-10
140
3010
5020
6830
8640 50
104
122¡CTemp.
¡F
10W-30
10W-40
20W-40
20W-50
15W-40

2

2

SPEC

2 - 10
MAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S
´
1.0 1 13 1.3 9.4
Camshaft cap M6
´
1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12
´
1.0 1 37 3.7 27
Cylinder head (stud bolt) M6
´
1.0 2 7 0.7 5.1
(stud bolt) M8
´
1.25 1 15 1.5 11
(bolt) M9
´
1.25 4 38 3.8 27
(nut) M6
´
1.0 2 10 1.0 7.2
Cylinder head cover M6
´
1.0 2 10 1.0 7.2
Oil pressure check bolt M6
´
1.0 1 10 1.0 7.2
Cylinder M6
´
1.0 1 10 1.0 7.2
Balancer weight M6
´
1.0 2 10 1.0 7.2
Balancer shaft driven gear M14
´
1.0 1 50 5.0 36
Timing chain guide (intake side) M6
´
1.0 2 10 1.0 7.2
Decompression shaft M6
´
1.0 1 7 0.7 5.1
Decompression cable guide M6
´
1.0 1 10 1.0 7.2
Timing chain tensioner M6
´
1.0 2 10 1.0 7.2
Timing chain tensioner cap bolt M6
´
1.0 1 7 0.7 5.1
Impeller M8
´
1.25 1 14 1.4 10
Radiator hose clamp M6
´
1.0 8 2 0.2 1.4
Coolant drain bolt M6
´
1.0 1 10 1.0 7.2
Water pump housing M6
´
1.0 4 10 1.0 7.2
Radiator M6
´
1.0 6 10 1.0 7.2
Radiator guard M6
´
1.0 2 10 1.0 7.2
Radiator pipe M6
´
1.0 1 10 1.0 7.2
Oil pump cover M4
´
0.7 1 3 0.3 2.2
Oil pump M6
´
1.0 3 10 1.0 7.2
Oil filter element drain bolt M6
´
1.0 1 10 1.0 7.2
Oil filter element cover M6
´
1.0 2 10 1.0 7.2
Oil strainer M6
´
1.0 2 10 1.0 7.2
Oil delivery pipe 1 (M10) M10 ´ 1.25 1 20 2.0 14
(M8) M8 ´ 1.25 2 18 1.8 13
Oil delivery pipe 2 M6 ´ 1.0 1 10 1.0 7.2
Oil hose M6 ´ 1.0 3 10 1.0 7.2
Oil hose clamp — 2 2 0.2 1.4
Oil strainer and frame M18 ´ 1.5 1 90 9.0 65
Carburetor joint clamp M4 ´ 0.7 2 3 0.3 2.2
Air filter joint clamp M6 ´ 1.0 1 3 0.3 2.2
Throttle cable cover M5 ´ 0.8 1 4 0.4 2.9
Air filter joint M5 ´ 0.8 2 5 0.5 3.6
Air filter joint and air filter case M5 ´ 0.8 5 1 0.1 0.7
Air filter element M6 ´ 1.0 1 2 0.2 1.4
Air filter case cover M6 ´ 1.0 4 4 0.4 2.9
Exhaust pipe (nut) M8 ´ 1.25 1 13 1.3 9.4
(bolt) M8 ´ 1.25 1 24 2.4 17
Exhaust pipe protector M6 ´ 1.0 3 10 1.0 7.2

SPEC
2 - 18
EC220001
GENERAL TORQUE SPECIFICATIONS
This chart specifies torque for standard fasten-
ers with standard I.S.O. pitch threads. Torque
specifications for special components or
assemblies are included in the applicable sec-
tions of this book. To avoid warpage, tighten
multi-fastener assemblies in a crisscross fash-
ion, in progressive stages, until full torque is
reached. Unless otherwise specified, torque
specifications call for clean, dry threads. Com-
ponents should be at room temperature.
A: Distance between flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
A
(Nut)B
(Bolt)TORQUE
SPECIFICATION
Nm m•kg ft•lb
10 mm
12 mm
14 mm
17 mm
19 mm
22 mm6 mm
8 mm
10 mm
12 mm
14 mm
16 mm6
15
30
55
85
1300.6
1.5
3.0
5.5
8.5
134.3
11
22
40
61
94
Unit Read Definition Measure
mm
cmmillimeter
centimeter10
-3 meter
10-2 meterLength
Length
kg kilogram 10
3 gram Weight
N Newton 1 kg ´ m/sec
2 Force
Nm
m • kgNewton meter
Meter kilogramN ´ m
m ´ kgTorque
Torque
Pa Pascal N/m
2Pressure
N/mm Newton per millimeter N/mm Spring rate
L
cm
3 Liter
Cubic centimeter—
—Volume or capacity
Volume or capacity
r/min Revolution per minute — Engine speed
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS

3 - 46
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable end
0Decompression cable endUse Yamaha cable lube or equivalent on these
areas.
õUse SAE 10W-30 motor oil or suitable chain
lubricants.
‚Lubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC

4 - 12
ENGCARBURETOR
Float height
1. Measure:
lFloat height a
Out of specification ® Adjust.
Float height:
8.0 mm (0.31 in)
Measurement and adjustment steps:
lHold the carburetor in an upside down
position.
NOTE:
lSlowly tilt the carburetor in the opposite
direction, then take the measurement
when the needle valve aligns with the float
arm.
lIf the carburetor is level, the weight of the
float will push in the needle valve, result-
ing in an incorrect measurement.
lMeasure the distance between the mating
surface of the float chamber and top of the
float using a vernier calipers.
NOTE:
The float arm should be resting on the nee-
dle valve, but not compressing the needle
valve.
lIf the float height is not within specifica-
tion, inspect the valve seat and needle
valve.
lIf either is worn, replace them both.
lIf both are fine, adjust the float height by
bending the float tab b on the float.
lRecheck the float height.
EC464600
Float
1. Inspect:
lFloat 1
Damage ® Replace.

4 - 64
ENGBALANCER
REMOVAL POINTS
Balancer shaft drive gear and balancer
shaft driven gear
1. Straighten the lock washer tab.
2. Loosen:
lNut (primary drive gear) 1
lNut (balancer shaft driven gear) 2
NOTE:
Place an aluminum plate a between the teeth
of the balancer shaft drive gear 3 and driven
gear 4.
Balancer shaft
1. Remove:
lBalancer shaft 1
NOTE:
When removing the balancer shaft, align the
center a of the balancer shaft weight along
the line connecting the centers of the crank-
shaft and balancer shaft.
INSPECTION
Primary drive gear, balancer shaft drive
gear and balancer shaft driven gear
1. Inspect:
lPrimary drive gear 1
lBalancer shaft drive gear 2
lBalancer shaft driven gear 3
Wear/damage ® Replace.
Balancer shaft
1. Inspect:
lBalancer shaft
Cracks/damage ® Replace.

4 - 65
ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer shaft, balancer shaft drive gear
and balancer shaft driven gear
1. Install:
lBalancer shaft 1
NOTE:
lApply the engine oil on the bearing.
lWhen installing the balancer shaft, align the
center a of the balancer shaft weight along
the line connecting the centers of the crank-
shaft and balancer shaft.
2. Install:
lBalancer shaft driven gear 1
NOTE:
Install the balancer shaft driven gear onto the
balancer shaft while aligning the punch mark
a on the balancer shaft driven gear with the
lower spline b on the balancer shaft end.
3. Install:
lBalancer shaft drive gear 1
NOTE:
lAlign the punched mark a on the balancer
shaft drive gear with the punched mark b on
the balancer shaft driven gear 2.
lAlign the punched mark c on the balancer
shaft drive gear with the lower spline d on
the crankshaft end.
4. Install:
lLock washer 1
lNut (balancer shaft driven gear) 2
lPrimary drive gear 3
lNut (primary drive gear) 4
NOTE:
lInstall the primary drive gear with its stepped
side a facing the engine.
lPlace an aluminum plate b between the
teeth of the balancer shaft drive gear 5 and
driven gear 6.
5. Bend the lock washer tab.
T R..50 Nm (5.0 m · kg, 3.6 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)