2007 YAMAHA YZ250F engine

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 5XCG G0 5XCH H0 ----
Main jet (M.J) #178
←----
Main air jet (M.A.J)ø2.0
←----
Jet needle – clip position (J.N) OBEPQ-4
←----
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) 1-7/8 2-1/8 ----
Bypass (B.P)ø1.0
←----
Valve seat size (V.S)ø3.8
←----
Starter jet (G.S) #72
←----
Leak jet (Acc.P) #80 #70 ----
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 19 1.9 12
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 M8 × 1.25 4 34 3.4 25
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 9 0.9 6.5
Fuel cock M6 × 1.0 2 4 0.4 2.9
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 - 20
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Fuel tank breather hose
2Radiator hose 1
3Connector cover
4Cylinder head breather hose
5Radiator hose 4
6Clutch cable
7Throttle position sensor lead
8Carburetor breather hose
9Upper engine bracket0Hot starter cable
AFuel hose
BCarburetor overflow hose

2 - 21
SPEC
ÈInsert the end of the fuel tank breather hose into
the hole in the steering stem.
ÉInstall the connector cover so that it does not
come in between the radiator hose 1 and radia-
tor.
ÊAligh the paint mark on the cylinder head
breather hose with the front end of the hose
guide.
ËPass the cylinder head breather hose on the out-
side of the radiator hose 1 and then between the
radiator 4 and frame.ÌPass the clutch cable through the cable guide.
ÍPass the clutch cable in front of the radiator
mounting boss.
ÎPass the fuel hose between the hot starter cable
and throttle position sensor lead.
ÏPass the carburetor breater hoses so that they
are not pinched between the upper engine
bracket and carburetor.
ÐPass the carburetor breather hoses and over-
flow hose so that all there hoses do not contact
the rear shock absorber.
CABLE ROUTING DIAGRAM

2 - 22
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.

2 - 23
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.
CABLE ROUTING DIAGRAM

2 - 26
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