2009 YAMAHA YZ250F Engine

2-13
TIGHTENING TORQUES
△Brake caliper and bleed screw M8 × 1.25 2 6 0.6 4.3
△Front wheel axle and axle nut M16 × 1.5 1 105 10.5 75
△Front wheel axle holder M8 × 1.25 4 21 2.1 15
△Front brake disc M6 × 1.0 6 12 1.2 8.7
△Rear brake disc M6 × 1.0 6 14 1.4 10
△Footrest bracket and frame M10 × 1.25 4 55 5.5 40
△Brake pedal M8 × 1.25 1 26 2.6 19
△Rear brake master cylinder M6 × 1.0 2 10 1.0 7.2
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
△Rear brake hose union bolt M10 × 1.25 2 30 3.0 22
△Rear wheel axle and axle nut M22 × 1.5 1 135 13.5 98
△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 38 3.8 27
△Rear frame (lower) M8 × 1.25 2 32 3.2 23
△Swingarm and brake hose holder M5 × 0.8 4 3 0.3 2.2
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 2.9Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-15
TIGHTENING TORQUES
GENERAL TORQUE
SPECIFICATIONS
This chart specifies torque for stan-
dard fasteners with standard I.S.O.
pitch threads. Torque specifications
for special components or assem-
blies are included in the applicable
sections of this book. To avoid
warpage, tighten multi-fastener as-
semblies in a crisscross fashion, in
progressive stages, until full torque is
reached. Unless otherwise specified,
torque specifications call for clean,
dry threads. Components should be
at room temperature.A. Distance between flats
B. Outside thread diameter
DEFINITION OF UNITS
A
(Nut)B
(Bolt
)TORQUE SPECIFI-
CATION
Nm m•kg ft•lb
10
mm6 mm 6 0.6 4.3
12
mm8 mm 15 1.5 11
14
mm10
mm30 3.0 22
17
mm12
mm55 5.5 40
19
mm14
mm85 8.5 61
22
mm16
mm130 13 94
Unit Read Definition Measure
mm
millimeter 10-3 meter Length
cmcentimeter 10-2 meter Length
kgkilogram 103 gram Weight
NNewton 1 kg × m/sec2Force
NmNewton meter N × m Torque
m•kgMeter kilogram m × kg Torque
PaPascal N/m2Pressure
N/mmNewton per millimeter N/mm Spring rate
LLiter — Volume or capacity
cm3Cubic centimeter — Volume or capacity
r/minRevolution per minute — Engine speed

2-18
CABLE ROUTING DIAGRAM
CABLE ROUTING DIAGRAM
1. Fuel tank breather hose
2. Radiator hose 1
3. Connector cover
4. Cylinder head breather hose
5. Radiator hose 4
6. Clutch cable
7. Throttle position sensor lead
8. Carburetor breather hose
9. Upper engine bracket10. Hot starter cable
11. Fuel hose
12. Carburetor overflow hose
A. Insert the end of the fuel tank
breather hose into the hole in
the steering stem.
B. Install the connector cover so
that it does not come in between
the radiator hose 1 and radiator.C. Aligh the paint mark on the cylin-
der head breather hose with the
front end of the hose guide.
D. Pass the cylinder head breather
hose on the outside of the radia-
tor hose 1 and then between the
radiator 4 and frame.
E. Pass the clutch cable through
the cable guide.

2-19
CABLE ROUTING DIAGRAM
F. Pass the clutch cable in front of
the radiator mounting boss.
G. Pass the fuel hose on the out-
side of throttle position sensor
lead.
H. Pass the carburetor breater hos-
es so that they are not pinched
between the upper engine
bracket and carburetor.
I. Pass the carburetor breather
hoses and overflow hose so that
all there hoses do not contact
the rear shock absorber.

2-20
CABLE ROUTING DIAGRAM
1. Hot starter cable
2. Radiator hose 2
3. Clamp
4. Ignition coil lead
5. Throttle position sensor lead
6. Hump (frame)
7. Oil hose
8. Hose guide
9. Neutral switch lead
10. CDI magneto lead
11. Clutch cable12. Radiator breather hose
13. Engine stop switch lead
14. Sub-wire harness
15. CDI unit bracket
16. CDI unit
17. Throttle cable
18. Cylinder head breather hose
19. Hot starter cable protector
20. Rubber capA. Fasten the hot starter cable,
throttle cables, throttle position
sensor lead and ignition coil
lead.
B. Fasten the neutral switch lead
on the oil hose.
C. Pass the neutral switch lead on
the inside of the oil hose.
D. Fasten the neutral switch lead,
CDI magneto lead and radiator
breather hose.

2-21
CABLE ROUTING DIAGRAM
E. Fasten the neutral switch lead,
CDI magneto lead, radiator
breather hose and clutch cable
over the radiator mounting boss.
F. Pass the radiator breather hose
in front of the radiator, on the left
of the chassis, and then be-
tween the frame and radiator
hose 4.
G. Fasten the sub-wire harness
and engine stop switch lead to
the CDI unit bracket at the white-
taped portion of the subwire har-
ness and with the clamp ends
facing downward.
H. Locate the clamp ends in the ar-
rowed range.
I. Fasten the neutral switch lead
and CDI magneto lead over the
hump of the frame.
J. Fasten the hot starter cable and
throttle cable onto the frame.
K. Fasten the throttle position sen-
sor lead and the hot starter ca-
ble.
L. Locate the clamp between the
hot starter cable protector and
rubber cap.
M. Locate the clamp ends under
the throttle cable, and after
clamping, leave the other end as
is and do not cut it. [clamp:L=
270mm (10.6 in)]

2-24
CABLE ROUTING DIAGRAM
1. Throttle cable
2. Clamp
3. Hot starter cable
4. Clutch cable
5. Engine stop switch lead
6. Cable guide
7. Brake hose
8. Hose guide
A. Fasten the engine stop switch
lead to the handlebar.B. Pass the clutch cable and hot
starter cable through the cable
guide.
C. Pass the brake hose in front of
the number plate.
D. Pass the throttle cables through
the cable guide.
E. Pass the clutch cable and hot
starter cable through the cable
guide on the number plate.

3-1
MAINTENANCE INTERVALS
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as
weather, terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals. If
you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks
ENGINE OIL
Replace●●
Inspect●●
OIL FILTER ELEMENT, OIL
STRAINER
Clean●
VALVES
Check the valve clearances●●The engine must be cold.
Inspect●Check the valve seats and valve
stems for wear.
Replace●
VALVE SPRINGS
Inspect●Check the free length and the tilt.
Replace●
VALVE LIFTERS
Inspect●Check for scratches and wear.
Replace●
CAMSHAFTS Inspect the camshaft surface.
Inspect●Inspect the decompression system.
Replace●
TIMING CHAIN SPROCKETS,
TIMING CHAIN
Inspect●Check for wear on the teeth and for
damage.
Replace●
PISTON
Inspect●●Inspect crack.
Clean●Inspect carbon deposits and eliminate
them.
Replace●
PISTON RING
Inspect●Check ring end gap.
Replace●●
PISTON PIN
Inspect●
Replace●
CYLINDER HEAD Inspect carbon deposits and eliminate
them.
Inspect and clean●Change gasket.
3