engine YAMAHA YZ250F 2006 Owner's Manual

1 - 20
GEN
INFO
CLEANING AND STORAGE
EC1B2001
STORAGE
If your machine is to be stored for 60 days or
more, some preventive measures must be
taken to avoid deterioration. After cleaning the
machine thoroughly, prepare it for storage as
follows:
1. Drain the fuel tank, fuel lines, and the car-
buretor float bowl.
2. Remove the spark plug, pour a tablespoon
of SAE 10W-30 motor oil in the spark plug
hole, and reinstall the plug. With the engine
stop switch pushed in, kick the engine over
several times to coat the cylinder walls with
oil.
3. Remove the drive chain, clean it thoroughly
with solvent, and lubricate it. Reinstall the
chain or store it in a plastic bag tied to the
frame.
4. Lubricate all control cables.
5. Block the frame up to raise the wheels off
the ground.
6. Tie a plastic bag over the exhaust pipe out-
let to prevent moisture from entering.
7. If the machine is to be stored in a humid or
salt-air environment, coat all exposed
metal surfaces with a film of light oil. Do not
apply oil to rubber parts or the seat cover.
NOTE:
Make any necessary repairs before the
machine is stored.

SPEC
2 - 1
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: YZ250FV (USA, CDN, AUS, NZ)
YZ250F (EUROPE, ZA)
Model code number: 5XC9, 5XCD (USA, CDN)
5XCA (EUROPE)
5XCC, 5XCF (AUS, NZ, ZA)
Dimensions:
USA, CDN, ZAEUROPE
(Except for F)F
Overall length 2,176 mm
(85.67 in)2,170 mm
(85.43 in)2,169 mm
(85.39 in)
Overall width 815 mm
(32.09 in)← ←
Overall height 1,292 mm
(50.87 in)1,294 mm
(50.94 in)←
Seat height 983 mm
(38.7 in)994 mm
(39.13 in)993 mm
(39.09 in)
Wheelbase 1,485 mm
(58.46 in)1,473 mm
(57.99 in)←
Minimum ground clearance 369 mm
(14.53 in)371 mm
(14.61 in)←
Dry weight:
Without oil and fuel 93.5 kg (206 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
2
GENERAL SPECIFICATIONS

SPEC
2 - 2 Oil type or grade:
Engine oil (For USA and CDN)
At 5 °C (40 °F) or higher È
Yamalube 4 (20W-40) or SAE 20W-40 type
SG motor oil
(Non-Friction modified)
At 15 °C (60 °F) or lower É
Yamalube 4 (10W-30) or SAE 10W-30 type
SG motor oil
(Non-Friction modified)
and/or
Yamalube 4-R (15W-50)
(Non-Friction modified)
(Except for USA and CDN)
API “SG” or higher grade
Oil capacity:
Engine oil
Periodic oil change 1.15 L (1.01 Imp qt, 1.22 US qt)
With oil filter replacement 1.25 L (1.10 Imp qt, 1.32 US qt)
Total amount 1.40 L (1.23 Imp qt, 1.48 US qt)
Coolant capacity (including all routes): 0.99 L (0.87 Imp qt, 1.05 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a
research octane number of 95 or higher.
Tank capacity 7.0 L (1.54 Imp gal, 1.85 US gal)
Carburetor:
Type FCR-MX37
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK (resistance type)
Gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type: Wet, multiple-disc
-20
-4-10
140
3010
5020
6830
8640 50
104
122 ˚CTemp.
˚F
10W-30
10W-40
20W-40
20W-50
15W-40
GENERAL SPECIFICATIONS

2

SPEC
2 - 4
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Cylinder head:
Warp limit ---- 0.05 mm
(0.002 in)
Cylinder:
Bore size 77.00 ~ 77.01 mm
(3.0315 ~ 3.0319 in)----
Out of round limit ---- 0.05 mm
(0.002 in)
Camshaft:
Drive method Chain drive (Left) ----
Camshaft cap inside diameter 22.000 ~ 22.021 mm
(0.8661 ~ 0.8670 in)----
Camshaft outside diameter 21.959 ~ 21.972 mm
(0.8645 ~ 0.8650 in)----
Shaft-to-cap clearance 0.028 ~ 0.062 mm
(0.0011 ~ 0.0024 in)0.08 mm
(0.003 in)
Cam dimensions
Intake“A”30.296 ~ 30.346 mm
(1.1923 ~ 1.1947 in)30.196 mm
(1.1888 in)
“B”22.45 ~ 22.55 mm
(0.8839 ~ 0.8878 in)22.35 mm
(0.8799 in)
Exhaust“A”30.399 ~ 30.499 mm
(1.1968 ~ 1.2007 in)30.299 mm
(1.1929 in)
“B”22.45 ~ 22.55 mm
(0.8839 ~ 0.8878 in)22.35 mm
(0.8799 in)
Camshaft runout limit ---- 0.03 mm
(0.0012 in)
A
B
MAINTENANCE SPECIFICATIONS

SPEC
2 - 8 Clutch plate thickness 1.1 ~ 1.3 mm (0.043 ~ 0.051 in) ----
Quantity 8 ----
Warp limit ---- 0.1 mm
(0.004 in)
Clutch spring free length 40.4 mm (1.59 in) 39.4 mm
(1.55 in)
Quantity 5 ----
Clutch housing thrust clearance 0.10 ~ 0.35 mm
(0.0039 ~ 0.0138 in)----
Clutch housing radial clearance 0.010 ~ 0.044 mm
(0.0004 ~ 0.0017 in)----
Clutch release method Inner push, cam push ----
Shifter:
Shifter type Cam drum and guide bar ----
Guide bar bending limit ---- 0.05 mm
(0.002 in)
Kickstarter:
Type Kick and ratchet type ----
Carburetor:
USA, CDNEUROPE, ZA,
AUS, NZ
Type/manufacturer FCR-MX37/
KEIHIN
←----
I. D. mark 5XC9 90 5XCA A0 ----
Main jet (M.J) #178 #175 ----
Main air jet (M.A.J)ø2.0
←----
Jet needle – clip position (J.N) OBELQ-3 OBEKP-3 ----
Cutaway (C.A) 1.5
←----
Pilot jet (P.J) #42
←----
Pilot air jet (P.A.J) #105
←----
Pilot outlet (P.O)ø0.9
←----
Pilot screw (example) (P.S) 2-1/2 2-1/4 ----
Bypass (B.P)ø1.0
←----
Valve seat size (V.S)ø3.8
←----
Starter jet (G.S) #72
←----
Leak jet (Acc.P) #80 #85 ----
Float height (F.H) 8 mm (0.31 in)
←----
Engine idle speed 1,900 ~
2,100 r/min
←----
Intake vacuum
29.3 ~ 34.7 kPa
(220 ~ 260 mmHg,
8.66 ~ 9.45 inHg)←----
Hot starter lever free play 3 ~ 6 mm
(0.12 ~ 0.24 in)
←---- Item Standard Limit
MAINTENANCE SPECIFICATIONS

SPEC
2 - 15
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Nipple (spoke)—72 3 0.3 2.2
Rear wheel sprocket M8 × 1.25 6 42 4.2 30
Rear brake disc cover M6 × 1.0 2 10 1.0 7.2
Rear brake caliper protector M6 × 1.0 2 7 0.7 5.1
Drive chain puller adjust bolt and locknut M8 × 1.25 2 16 1.6 11
Engine mounting:
Engine and engine bracket (front) M10 × 1.25 1 53 5.3 38
Engine and frame (lower) M10 × 1.25 1 53 5.3 38
Upper engine bracket and frame M10 × 1.25 4 55 5.5 40
Lower engine bracket and frame M8 × 1.25 4 38 3.8 27
Engine and engine bracket (upper) M10 × 1.25 1 55 5.5 40
Lower engine guard M6 × 1.0 3 10 1.0 7.2
Right engine guard M6 × 1.0 1 10 1.0 7.2
CDI unit bracket M6 × 1.0 2 7 0.7 5.1
Cable guide and CDI unit bracket M5 × 0.8 2 4 0.4 2.9
Cable guide and frame M5 × 0.8 1 5 0.5 3.6
Pivot shaft and nut M16 × 1.5 1 85 8.5 61
Relay arm and swingarm M14 × 1.5 1 70 7.0 50
Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
Connecting rod and frame M14 × 1.5 1 80 8.0 58
Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
Rear frame (upper) M8 × 1.25 1 32 3.2 23
Rear frame (lower) M8 × 1.25 2 32 3.2 23
Swingarm and brake hose holder M5 × 0.8 4 2 0.2 1.4
Swingarm and patch M4 × 0.7 4 2 0.2 1.4
Upper drive chain tensioner M8 × 1.25 1 16 1.6 11
Lower drive chain tensioner M8 × 1.25 1 16 1.6 11
Drive chain support M6 × 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
Fuel tank mounting boss and frame M10 × 1.25 1 20 2.0 14
Fuel tank M6 × 1.0 2 10 1.0 7.2
Fuel cock M6 × 1.0 2 6 0.6 4.3
Seat set bracket and fuel tank M6 × 1.0 1 7 0.7 5.1
Fuel tank bracket and fuel tank M6 × 1.0 4 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 6 7 0.7 5.1
Air scoop and radiator guard (lower) M6 × 1.0 2 7 0.7 5.1
Front fender M6 × 1.0 4 7 0.7 5.1
Rear fender (front) M6 × 1.0 2 7 0.7 5.1
Rear fender (rear) M6 × 1.0 2 16 1.6 11
Side cover M6 × 1.0 2 7 0.7 5.1
Seat M8 × 1.25 2 23 2.3 17
Number plate M6 × 1.0 1 7 0.7 5.1
MAINTENANCE SPECIFICATIONS

SPEC
2 - 17
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 mkg ftlb
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

2 - 19
SPECCABLE ROUTING DIAGRAM
1Hot starter cable
2Radiator hose 2
3Clamp
4Ignition coil lead
5Throttle position sensor lead
6Hump (frame)
7Oil hose
8Hose guide
9Neutral switch lead
0CDI magneto lead
AClutch cable
BRadiator breather hose
CEngine stop switch leadDSub-wire harness
ECDI unit bracket
FCDI unit
GThrottle cable
HCylinder head breather hose
ÈFasten the hot starter cable,
throttle cables, throttle position
sensor lead and ignition coil
lead.
ÉFasten the throttle position
sensor lead behind the hump
of the frame.ÊFasten the neutral switch lead
on the oil hose.
ËPass the neutral switch lead on
the inside of the oil hose.
ÌFasten the neutral switch lead,
CDI magneto lead and radiator
breather hose.
ÍFasten the neutral switch lead,
CDI magneto lead, radiator
breather hose and clutch cable
over the radiator mounting
boss.
5Ð
Ð
B-B
C-C
E-E
H-H
G-G
D-D
A-A
G
4
5
1
7H
Ð B
B
0
9 F
3
Ñ
6 90F
È
9
CC
C E HH
GA
AB
E
7
3
8 3 9
Ê Ê
Ë
F
E
3
D
C
B
3
A
3
Ì Í Î Ï
1
2
3
4
5
6
3
B
0
9
A
0É
B
B 0 9
9
D
G
B
D
Ò 3

2 - 20
SPEC
ÎPass the radiator breather
hose in front of the radiator, on
the left of the chassis, and then
between the frame and radiator
hose 4.
ÏFasten the sub-wire harness
and engine stop switch lead to
the CDI unit bracket at the
white-taped portion of the sub-
wire harness and with the
clamp ends facing downward.ÐLocate the clamp ends in the
arrowed range.
ÑFasten the neutral switch lead
and CDI magneto lead over the
hump of the frame.
ÒFasten the hot starter cable
and throttle cable onto the
frame. Locate the clamp ends
under the hot starter cable.
5Ð
Ð
B-B
C-C
E-E
H-H
G-G
D-D
A-A
G
4
5
1
7H
Ð B
B
0
9 F
3
Ñ
6 90F
È
9
CC
C E HH
GA
AB
E
7
3
8 3 9
Ê Ê
Ë
F
E
3
D
C
B
3
A
3
Ì Í Î Ï
1
2
3
4
5
6
3
B
0
9
A
0É
B
B 0 9
9
D
G
B
D
Ò 3
CABLE ROUTING DIAGRAM

2 - 23
SPECCABLE ROUTING DIAGRAM
1Throttle cable
2Clamp
3Hot starter cable
4Clutch cable
5Engine stop switch lead
6Cable guide
7Brake hose
8Hose guideÈFasten the engine stop switch lead to the handle-
bar.
ÉPass the clutch cable and hot starter cable
through the cable guide.
ÊPass the brake hose in front of the number plate.
ËPass the throttle cables through the cable guide.
ÌPass the clutch cable and hot starter cable
through the cable guide on the number plate.
A
B
C
A
B
C40˚± 10˚
40˚± 10˚
2
È3
2
5
4
2
3
5
6
Ë1
4
5
7
Ê
6
É
Ì
8