2005 YAMAHA YZ250LC width

2-1
GENERAL SPECIFICATIONSSPEC
Model name: YZ250T1 (USA, CDN)
YZ250 (EUROPE, ZA)
YZ250T (AUS, NZ)
Model code number: 1P81 (USA, CDN, ZA)
1P82 (EUROPE)
1P84 (AUS, NZ)
Dimensions:USA, ZAAUS, NZ EUROPE CDN
Overall length 2,179 mm←2,188 mm 2,186 mm
(85.8 in) (86.1 in) (86.1 in)
Overall width 827 mm←←←
(32.6 in)
Overall height 1,306 mm←1,310 mm 1,309 mm
(51.4 in) (51.6 in) (51.5 in)
Seat height 989 mm←992 mm←
(38.9 in) (39.1 in)
Wheelbase 1,481 mm←1,485 mm←
(58.3 in) (58.5 in)
Minimum ground clearance 383 mm←386 mm←
(15.1 in) (15.2 in)
Dry weight:
Without oil and fuel 96.0 kg (211.6 lb)
Engine:
Engine type Liquid cooled 2-stroke, gasoline
Cylinder arrangement Single cylinder, forward inclined
Displacement 249 cm
3(8.76 lmp oz, 8.42 US oz)
Bore ×Stroke 66.4 ×72 mm (2.614 ×2.835 in)
Compression ratio 9.1~10.9 : 1 (Expect for EUROPE)
9.0~10.6 : 1 (For EUROPE)
Starting system Kick starter
Lubrication system: Premix (30 : 1)(Yamalube 2-R)
Oil type or grade (2-Cycle):
Transmission oil Yamalube 4 (10W-30) or SAE 10W-30 type SE
motor oil
Periodic oil change 0.75 L (0.66 Imp qt, 0.79 US qt)
Total amount 0.80 L (0.70 Imp qt, 0.85 US qt)
Coolant capacity (including all routes): 1.20 L (1.06 Imp qt, 1.27 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline
only with a research octane
number of 95 or higher
Tank capacity 8.0 L (1.76 Imp gal, 2.11 US gal)
EC200000
SPECIFICATIONSEC211000
GENERAL SPECIFICATIONS
1P8-9-30-2 19/5/04 9:08 AM Page 2

2-3
MAINTENANCE SPECIFICATIONSSPEC
Item Standard Limit
Cylinder head:USA, CDN, ZA,
EUROPE
AUS, NZ
Combustion chamber capacity 21.0 cm
321.5 cm3…
(0.739 Imp oz, (0.757 Imp oz,
0.710 US oz) 0.727 US oz)
Warp limit……
0.03 mm (0.0012 in)
Cylinder:
Bore size 66.400~66.414 mm 66.5 mm (2.618 in)
(2.6142~2.6147 in)
Taper limit…
0.05 mm (0.0020 in)
Out of round limit…
0.01 mm (0.0004 in)
Piston:
Piston size/ 66.352~66.367 mm…
(2.6120~2.6129 in)
Measuring point* 17.5 mm (0.69 in)…
Piston clearance 0.045~0.050 mm 0.1 mm (0.004 in)
(0.0018~0.0020 in)
Piston offset 1.5 mm (0.059 in)/EX-side…
Piston pin:
Piston pin outside diameter 17.995~18.000 mm 17.975 mm
(0.7085~0.7087 in) (0.7077 in)
Piston ring:
Sectional sketch Plain…
B=1.0 mm (0.039 in)…
T=2.55 mm (0.100 in)…
End gap (installed) 0.40~0.55 mm (0.016~0.022 in) 0.95 mm (0.037 in)
Side clearance (installed) : 1st
0.030~0.065 mm (0.0012~0.0026 in)0.1 mm (0.004 in)
: 2nd0.030~0.065 mm (0.0012~0.0026 in)0.1 mm (0.004 in)
Crankshaft:
Crank width “A” 59.95~60.00 mm (2.360~2.362 in)…
Runout limit “C” 0.03 mm (0.0012 in) 0.05 mm (0.0020 in)
Connecting rod big end
side clearance “D” 0.25~0.75 mm (0.010~0.030 in)…
Small end free play “F” 0.4~1.0 mm (0.016~0.039 in) 2.0 mm (0.08 in)
Clutch:
Friction plate thickness 2.9~3.1 mm (0.114~0.122 in) 2.8 mm (0.110 in)
Quantity 8 …
Clutch plate thickness 1.5~1.7 mm (0.059~0.067 in) …
Quantity 7 …
Warp limit … 0.2 mm (0.008 in)
Clutch spring free length 50.0 mm (1.969 in) 48.0 mm (1.890 in)
Quantity 6 …
EC212000
MAINTENANCE SPECIFICATIONSEC212100
ENGINE
1P8-9-30-2 19/5/04 9:08 AM Page 4

2-4
MAINTENANCE SPECIFICATIONSSPEC
Item Standard Limit
Clutch housing thrust clearance 0.17~0.23 mm (0.007~0.009 in) …
Clutch housing radial clearance 0.030~0.055 mm (0.001~0.002 in) …
Clutch release method Inner push, cam push …
Transmission:
Main axle deflection limit…
0.01 mm (0.0004 in)
Drive axle deflection limit…
0.01 mm (0.0004 in)
Shifter:
Shifting type Cam drum and guide bar…
Guide bar bending limit…
0.05 mm (0.0020 in)
Kick starter type: Kick and ratchet type…
Air filter oil grade (oiled filter):Foam-air-filter oil or equivalent oil…
Carburetor:USA, CDN, ZA,
EUROPE
AUS, NZ
Type/Manufacturer
PWK38S/KEIHIN←…
I.D. mark 1P81 00 1P82 10…
Main jet (M.J.) #178 #180…
Main air jet (M.A.J) #200←…
Jet needle-clip position (J.N.) N3EJ-2 N3EW-3…
Main nozzle (N.J.) ø2.9←…
Cutaway (C.A.) #7←…
Pilot jet (P.J.) #50 #52…
Pilot air screw (P.A.S.) 1 7/8…
(for reference only)
Valve seat size (V.S.)
ø3.8 mm (0.15 in)←…
Starter jet (G.S.) #85←…
Power jet (P.W.J.) #50←…
Float arm height (F.H.) 5.5~7.5 mm←…
(0.22~030 in)
Reed valve:
Thickness* 0.42 mm (0.017 in)…
Valve stopper height 10.3~10.7 mm (0.406~0.421 in)…
Valve bending limit…
0.2 mm (0.008 in)
Cooling:
Radiator core size:
Width 107.8 mm (4.24 in)…
Height 240 mm (9.45 in)…
Thickness 32 mm (1.26 in)…
Radiator cap opening pressure 95~125 kPa…
(0.95~1.25 kg/cm
2, 13.5~17.8 psi)
Radiator capacity (total) 0.63 L (0.55 Imp qt, 0.67 US qt)…
Water pump:
Type Single-suction centrifugal pump…
1P8-9-30-2 19/5/04 9:08 AM Page 5

4-53
WATER PUMPENG
EC4G3000
REMOVAL POINTS
EC4G3110
Impeller shaft
1. Remove:
9Impeller 1
9Plain washer 2
9Impeller shaft 3
NOTE:
Hold the impeller shaft on its width across the
flats awith spanners, etc. and remove the
impeller.
EC4G3210
Oil seal
NOTE:
It is not necessary to disassemble the water
pump, unless there is an abnormality such as
excessive change in coolant level, discoloration
of coolant, or milky transmission oil.
1. Remove:
9Bearing 1
2. Remove:
9Oil seal 1
EC4G4000
INSPECTIONEC444200
Impeller shaft
1. Inspect:
9Impeller shaft 1
Bend/Wear/Damage
Replace.
Fur deposits
Clean.
1P8-9-30-4C 21/5/04 12:59 PM Page 8

4-55
WATER PUMPENG
EC4G5220
Impeller shaft
1. Install:
9Impeller shaft 1
NOTE:
9Take care so that the oil seal lip is not dam-
aged or the spring does not slip off its position.
9When installing the impeller shaft, apply the
lithium soap base grease on the oil seal lip and
impeller shaft. And install the shaft while turn-
ing it.
2. Install:
9Plain washer 1
9Impeller 2
NOTE:
Hold the impeller shaft on its width across the
flats awith spanners, etc. and install the
impeller.
3. Install:
9Dowel pin 1
9Gasket (water pump housing cover) 2
4. Install:
9Water pump housing cover 1
9Bolt (water pump housing cover) 2
9Copper washer (coolant drain bolt) 3
9Coolant drain bolt 4
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
14 Nm (1.4 m•kg, 10 ft•lb)
1P8-9-30-4C 21/5/04 12:59 PM Page 12

4-68
CRANKCASE AND CRANKSHAFTENG
EC4N5000
ASSEMBLY AND INSTALLATION
EC4N5300
Crankshaft bearing
1. Install:
9Bearing 1
To crankcase (left and right).
NOTE:
Install the bearing by pressing its outer race
parallel.
Standard
Runout 0.03 mm 0.05 mm
limit: (0.0012 in) (0.0020 in)
Small end 0.4~1.0 mm 2.0 mm
free play: (0.016~0.039 in) (0.08 in)
Side 0.25~0.75 mm
—
clearance: (0.010~0.030in)
Crank 59.95~60.00 mm
—
width: (2.360~2.362 in)
EC4N4202
Crankshaft
1. Measure:
9Runout limit a
9Small end free play limit b
9Connecting rod big end side clearance c
9Crank width d
Out of specification
Replace.
Use the dial gauge and a thickness gauge.
Dial gauge:
YU-3097/90890-01252
EC4N5102
Oil seal
1. Install:
9Oil seal (left) 1
9Oil seal (right) 2
NOTE:
9Apply the lithium soap base grease on the oil
seal lip.
9Install the oil seal with its manufacture’s marks
or numbers facing outward.
1P8-9-30-4C 21/5/04 1:00 PM Page 38