height YAMAHA YZ250F 2015 Owners Manual

GENERAL SPECIFICATIONS
2-1
EAS1SM5053
GENERAL SPECIFICATIONS
Model
Model 1SM5 (USA) (CAN)
1SM6 (EUR)
1SM7 (JPN)
1SM8 (AUS) (NZL) (ZAF)
Dimensions
Overall length 2165 mm (85.2 in) (USA) (CAN) (AUS) (NZL)
(ZAF)
2170 mm (85.4 in) (EUR) (JPN)
Overall width 825 mm (32.5 in)
Overall height 1280 mm (50.4 in) (USA) (CAN) (EUR) (JPN)
1275 mm (50.2 in) (AUS) (NZL) (ZAF)
Seat height 965 mm (38.0 in) (USA) (CAN) (EUR) (JPN)
960 mm (37.8 in) (AUS) (NZL) (ZAF)
Wheelbase 1475 mm (58.1 in)
Ground clearance 325 mm (12.8 in) (USA) (CAN) (AUS) (NZL)
(ZAF)
330 mm (13.0 in) (EUR) (JPN)
Weight
Curb weight 105 kg (231 lb)

ENGINE SPECIFICATIONS
2-2
EAS1SM5054
ENGINE SPECIFICATIONS
Engine
Engine type Liquid cooled 4-stroke, DOHC
Displacement 250 cm
3
Cylinder arrangement Single cylinder
Bore  stroke 77.0  53.6 mm (3.0  2.1 in)
Compression ratio 13.5:1
Starting system Kickstarter
Fuel
Recommended fuel Premium unleaded gasoline only
Fuel tank capacity 7.5 L (1.98 US gal, 1.65 Imp.gal)
Engine oil
Lubrication system Wet sump
Recommended brand YAMALUBE
Type SAE 10W-30, SAE 10W-40, SAE 10W-50,
SAE 15W-40, SAE 20W-40 or SAE 20W-50
Recommended oil grade API service SG type or higher, JASO standard
MA
Engine oil quantity
Quantity (disassembled) 0.90 L (0.95 US qt, 0.79 Imp.qt)
With oil filter element replacement 0.73 L (0.77 US qt, 0.64 Imp.qt)
Without oil filter element replacement 0.71 L (0.75 US qt, 0.62 Imp.qt)
Oil filter
Oil filter type Paper
Oil pump
Oil pump type Trochoid
Inner-rotor-to-outer-rotor-tip clearance Less than 0.150 mm (0.0059 in)
Limit 0.20 mm (0.0079 in)
Outer-rotor-to-oil-pump-housing clearance 0.13–0.18 mm (0.0051–0.0071 in)
Limit 0.24 mm (0.0094 in)
Oil-pump-housing-to-inner-and-outer-rotor
clearance 0.06–0.11 mm (0.0024–0.0043 in)
Limit 0.17 mm (0.0067 in)
Cooling system
Radiator capacity (including all routes) 1.00 L (1.06 US qt, 0.88 Imp.qt)
Radiator capacity 0.58 L (0.61 US qt, 0.51 Imp.qt)
Radiator cap opening pressure 108–137 kPa (1.08–1.37 kg/cm
2, 15.7–19.9
psi)
Radiator core
Width 112.6 mm (4.43 in)
Height 235.0 mm (9.25 in)
Depth 28.0 mm (1.10 in)
Water pump
Water pump type Single suction centrifugal pump
Spark plug
Manufacturer/model NGK/LMAR8G
Spark plug gap 0.7–0.8 mm (0.028–0.031 in)

ENGINE SPECIFICATIONS
2-5
Spring tilt (intake) 2.5 °/1.6 mm (2.5 °/0.06 in)
Spring tilt (exhaust) 2.5 °/1.5 mm (2.5 °/0.06 in)
Winding direction (intake) Clockwise
Winding direction (exhaust) Clockwise
Cylinder
Bore 77.000–77.010 mm (3.0315–3.0319 in)
Taper limit 0.050 mm (0.0020 in)
Out of round limit 0.050 mm (0.0020 in)
Piston
Piston-to-cylinder clearance 0.030–0.055 mm (0.0012–0.0022 in)
Limit 0.15 mm (0.006 in)
Diameter D 76.955–76.970 mm (3.0297–3.0303 in)
Height H 6.0 mm (0.24 in)
Offset 0.00 mm (0.0000 in)
Piston pin bore inside diameter 16.002–16.013 mm (0.6300–0.6304 in)
Limit 16.043 mm (0.6316 in)
Piston pin outside diameter 15.991–16.000 mm (0.6296–0.6299 in)
Limit 15.971 mm (0.6288 in)
Piston ring
Top ring
Ring type Barrel
Dimensions (B  T) 0.90  2.70 mm (0.04  0.11 in)
End gap (installed) 0.15–0.25 mm (0.0059–0.0098 in)
Limit 0.50 mm (0.0197 in)
Ring side clearance 0.030–0.065 mm (0.0012–0.0026 in)
Limit 0.120 mm (0.0047 in)
Oil ring
Dimensions (B  T) 1.50  2.25 mm (0.06  0.89 in)
End gap (installed) 0.10–0.35 mm (0.0039–0.0138 in)
H
D
T
B
B
T

MAINTENANCE INTERVALS
3-4
FUEL TANK, FUEL
PUMP
Inspect
FUEL HOSE
Inspect
Replace Every four years
FRONT FORK LEG
(S)
Clean Dust seal
Inspect and adjust
Replace oil
Replace oil seal
Clean and grease
oil seals and dust
sealsLithium soap base grease
PROTECTOR
GUIDE
Replace
REAR SHOCK AB-
SORBER
Inspect and adjust
Lubricate(After
rain
ride)Grease pillow balls and bear-
ings.
Retighten Check for tightening torques.
BRAKE(S)
Adjust lever posi-
tion and pedal
height
Lubricate pivot
point
Check brake disc
surface
Check fluid level
and leakage
Retighten brake
disc bolts, caliper
bolts, master cylin-
der bolts and union
boltsCheck for tightening torques.
Replace padsITEMAfter
break-
inEvery
race
(about
2.5
hours)Every
third
(about
7.5
hours)Every
fifth
(about
12.5
hours)As re-
quiredRemarks

CHASSIS
3-28
EAS1SM5100CHECKING THE FRONT FORK LEGS
1. Stand the vehicle upright on a level surface.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:
• Inner tube
Damage/scratches  Replace.
• Front fork leg (s)
Oil leaks between inner tube and outer tube
 Replace the oil seal.
3. Hold the vehicle upright and apply the front
brake.
4. Check:
• Front fork operation
Push down hard on the handlebar several
times and check if the front fork rebounds
smoothly.
Unsmooth operation  Correct or replace.
Refer to “FRONT FORK” on page 4-37.
EAS1SM5101CHECKING THE FRONT FORK PROTEC-
TOR GUIDE
1. Check:
• Protector guide “1”
Out of specification  Replace.
TIP
The protector guide reaches the limit of its use
when it is worn down to the same height “a” as
of the outer tube circumference.
EAS1SM5102
CLEANING THE FRONT FORK OIL SEAL
AND DUST SEAL
1. Remove:
•Protector
• Dust seal “1”
ECA?
NOTICE
Be careful not to damage the dust seal and
the inner tube by a driver.
2. Clean:
• Dust seal “a”
• Oil seal “b”
TIP
• Clean the dust seal and oil seal after every
run.
• Apply lithium-soap-based grease on the inner
tube.
EAS1SM5103AIR BLEEDING FROM FRONT FORK
TIP
If the front fork initial movement feels stiff dur-
ing a run, relieve the front fork internal pres-
sure.
1. Use a suitable stand to raise the front wheel
off the ground.
EWA@
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove the air bleed screw “1” and release
the internal pressure from the front fork.
1
a
1
LS
a
b

VALVES AND VALVE SPRINGS
5-24
EAS1SM5222CHECKING THE VALVES AND VALVE
GUIDES
1. Measure:
• Valve-stem-to-valve-guide clearance
Out of specification  Replace the valve
guide.2. Replace:
• Valve guide
TIP
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100 °C (212 °F) in an oven.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the valve guide with the valve guide
remover “1”.
b. Install the new valve guide with the valve
guide installer “2” and the valve guide re-
mover “1”.
c. After installing the valve guide, expand the
hole in the valve guide with the valve guide
reamer “3” to obtain the proper valve-stem-
to-valve-guide clearance. Valve-stem-to-valve-guide clearance =
Valve guide inside diameter “a” -
Valve stem diameter “b”
Valve-stem-to-valve-guide clear-
ance (intake)
0.010–0.037 mm (0.0004–0.0015
in)
Limit
0.080 mm (0.0032 in)
Valve-stem-to-valve-guide clear-
ance (exhaust)
0.025–0.052 mm (0.0010–0.0020
in)
Limit
0.100 mm (0.0039 in)
1
2
4
5
3
Valve guide installation height “a”
Intake
10.8–11.2 mm (0.43–0.44 in)
Exhaust
11.2–11.6 mm (0.44–0.46 in)
1