oil type YAMAHA YZ250LC 2004 Owners Manual

1-12
FUEL AND ENGINE MIXING OIL
GEN
INFO
EC160051
FUEL AND ENGINE MIXING OIL
Mix oil with the gas at the ratio specified below.
Always use fresh, name-brand gasoline, and mix
the oil and gas the day of the race. Do not use
premix that is more than a few hours old.
NOTE:
If knocking or pinging occurs, use a different
brand of gasoline or higher octane grade.
cC
Never mix two types of oil in the same
batch; clotting of the oil could result. If you
wish to change oil types, be sure to drain
the fuel tank and the carburetor float bowl
of old premix prior to filling with the new
type.
Fuel tank capacity:
8.0 L (1.76 Imp gal, 2.11 US gal)
Mixing oil
Recommended oil:
Yamalube “2-R”
(Yamalube racing 2-cycle oil)
Mixing ratio: 30 : 1
If unavailable, use an equivalent
type of oil.
Recommended fuel:
Except for ZA:
Premium unleaded gasoline
only with a research octane
number of 95 or higher.
For ZA:
Premium gasoline
5XF-9-30-1 4/22/03 8:54 AM Page 28

2-1
GENERAL SPECIFICATIONSSPEC
Model name: YZ250LC (EUROPE)
YZ250S (USA)
YZ250(S) (CDN, AUS, NZ, ZA)
Model code number: 5XF1 (USA, CDN, ZA)
5XF2 (EUROPE)
5XF4 (AUS, NZ)
Dimensions:USA, ZAAUS, NZ EUROPE CDN
Overall length 2,183 mm←2,182 mm←
(85.9 in) (85.9 in)
Overall width 827 mm←←←
(32.6 in)
Overall height 1,309 mm 1,296 mm 1,302 mm 1,307 mm
(51.5 in) (51.0 in) (51.3 in) (51.5 in)
Seat height 991 mm←990 mm←
(39.0 in) (39.0 in)
Wheelbase 1,481 mm←1,485 mm←
(58.3 in) (58.5 in)
Minimum ground clearance 395 mm←393 mm←
(15.6 in) (15.5 in)
Dry weight:
Without oil and fuel 97.0 kg (213.8 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 Except for ZA: Premium unleaded gasoline
only with a research octane
number of 95 or higher
For ZA: Premium gasoline
Tank capacity 8.0 L (1.76 Imp gal, 2.11 US gal)
EC200000
SPECIFICATIONSEC211000
GENERAL SPECIFICATIONS
5XF-9-30-2 5/15/03 3:54 PM Page 2

2-2
GENERAL SPECIFICATIONSSPEC
Carburetor:
Type/Manufacturer PWK38S/KEIHIN
Spark plug:
Type/Manufacturer BR8EG/NGK (resistance type)
Gap 0.5~0.6 mm (0.020~0.024 in)
Clutch type: Wet, multiple-disc
Transmission: USA, ZA, AUS, NZ EUROPE, CDN
Primary reduction system Gear←
Primary reduction ratio 63/21 (3.000)←
Secondary reduction system Chain drive←
Secondary reduction ratio 50/14 (3.571) 49/14 (3.500)
Transmission type Constant mesh,←
5-speed
Operation Left foot operation←
Gear ratio: 1st 27/14 (1.929)←
2nd 23/15 (1.533)←
3rd 23/18 (1.278)←
4th 24/22 (1.091)←
5th 20/21 (0.952)←
Chassis:USA, ZA, AUS, NZEUROPE, CDN
Frame type Semi double cradle←
Caster angle 27.0° 26.8°
Trail 118 mm (4.65 in) 114 mm (4.49 in)
Tire:
Type With tube
Size (front) 80/100-21 51M
Size (rear) 110/90-19 62M
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm2, 15 psi)
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/Gas, oil damper
Wheel travel:
Front wheel travel 300 mm (11.8 in)
Rear wheel travel 315 mm (12.4 in)
Electrical:
Ignition system CDI magneto
2
5XF-9-30-2 5/15/03 3:54 PM Page 3

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 5NX1 00 5UP2 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…
5XF-9-30-2 5/15/03 3:54 PM Page 5

2-7
MAINTENANCE SPECIFICATIONSSPEC
EC212201
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing…
Front suspension: USA, CDN, ZA,
EUROPE
AUS, NZ
Front fork travel
300 mm (11.8 in)←…
Fork spring free length
479 mm (18.9 in)←474 mm (18.7 in)
Spring rate, STD K=4.3 N/mm K=4.2 N/mm…
(0.438 kg/mm, (0.428 kg/mm)
24.5 lb/in) 24.0 lb/in
Optional spring/Spacer Yes←…
Oil capacity 664 cm
3662 cm3…
(23.4 Imp oz, (23.3 Imp oz,
22.45 US oz) 22.38 US oz)
Oil level
123 mm (4.84 in) 125 mm (4.92 in)…
105~135 mm ←…
(From top of outer tube with inner tube(4.13~5.31 in)
and damper rod fully compressed
without spring.)
Oil grade Suspension oil ←…
“01”
Inner tube outer diameter
48 mm (1.89 in)←…
Front fork top endZero mm (Zero in)←…
Rear suspension: USA, CDN, ZA,
EUROPE
AUS,NZ
Shock absorber travel
132 mm (5.20 in)←…
Spring free length
260 mm (10.24 in) 275 mm (10.83 in)…
Fitting length
245 mm (9.65 in)268 mm (10.55 in)…

240.5~258.5 mm 255.5~273.5 mm…
(9.47~10.18 in) (10.06~10.77 in)
Spring rate, STD K=46 N/mm K=Approx. 48 N/mm…
(4.7 kg/mm, (4.9 kg/mm,
263.2 lb/in) 274.4 lb/in)
Optional spring Yes←…
Enclosed gas pressure
1,000 kPa←…
(10 kg/cm2, 142 psi)
Swingarm:
Swingarm free play limit
End…
1.0 mm (0.04 in)
Side clearance…
0.2~0.9 mm
(0.008~0.035 in)
5XF-9-30-2 5/15/03 3:54 PM Page 8

2-11
MAINTENANCE SPECIFICATIONSSPEC
EC212300
ELECTRICAL
Part to be tightened Thread size Q’tyT ightening torqueNm m•kg ft•lb
Stator M 6 ×1.0 3 8 0.8 5.8
Rotor M12 ×1.25 1 56 5.6 40
Ignition coil M 6 ×1.0 2 7 0.7 5.1
Item Standard Limit
Ignition system:
Ignition timing (B.T.D.C.) 0.18 mm (0.007 in)…
Advancer type Electrical…
CDI:
Magneto-model (stator)/Manufacturer 5CU-02/YAMAHA…
Source coil 1 resistance (color) 720~1,080 Ωat 20°C (68°F)…
(Black-Black/Red)
Source coil 2 resistance (color) 44~66 Ωat 20°C (68°F)…
(Green/Blue-Green/White)
Pickup coil resistance (color) 248~372 Ωat 20°C (68°F)…
(White/Blue-White/Red)
CDI unit-model/Manufacturer 5NX-01/YAMAHA…
Ignition coil:
Model/Manufacturer 4MX-00/YAMAHA…
Minimum spark gap 6 mm (0.24 in)…
Primary winding resistance 0.20~0.30 Ωat 20°C (68°F)…
Secondary winding resistance 9.5~14.3 kΩat 20°C (68°F)…
Spark plug cap:
Resistance 4~6 kΩat 20°C (68°F)…
5XF-9-30-2 5/15/03 3:54 PM Page 12

2-8
CARACTERISTIQUES D’ENTRETIENSPEC
Article Standard Limite
Roue:
Type de roue avant Roue à rayons…
Type de roue arrière Roue à rayons…
Taille/matériau de jante avant 21 ×1,60/Aluminum…
Taille/matériau de jante arrière 19 ×2,15/Aluminum…
Limite de voile de jante:
Radial…
2,0 mm (0,08 in)
Latéral…
2,0 mm (0,08 in)
Chaîne de transmission:
Type/fabricant DID520DMA2 SDH/DAIDO…
Nombre de maillons 113 maillons + attache…
Flèche de la chaîne 40~50 mm (1,6~2,0 in)…
Longueur de chaîne (10 maillons)…
152,5 mm (6,004 in)
Frein à disque avant:
Dia. extérieur ×épaisseur 250 ×3,0 mm 250 ×2,5 mm
(9,84 ×0,12 in) (9,84 ×0,10 in)
Epaisseur de plaquette 4,4 mm (0,17 in) 1,0 mm (0,04 in)
Dia. intérieur de maître-cylindre 11,0 mm (0,433 in)…
Dia. intérieur de cylindre d’etrier 27,0 mm (1,063 in) ×2…
Type de liquide de frein DOT #4…
Frein à disque arrière:
Dia. extérieur ×épaisseur 245 ×4,0 mm 245 ×3,5 mm
(9,65 ×0,16 in) (9,65 ×0,14 in)
Limite de flèche…
0,15 mm (0,006 in)
Epaisseur de plaquette 6,4 mm (0,25 in) 1,0 mm (0,04 in)
Dia. intérieur de maître-cylindre 11,0 mm (0,433 in)…
Dia. intérieur de cylindre d’etrier 25,4 mm (1,000 in)…
Type de liquide de frein DOT #4…
Levier de frein & pédale de frein:
Position du levier de frein 95 mm (3,74 in)…
Hauteur de la pédale de frein Zéro mm (Zéro in)…
(hauteur au-dessus du haut du repose-pied)
Jeu de levier d’embrayage (côté levier) 8~13 mm (0,31~0,51 in)…
Jeu à la poignée d’accélération 3~5 mm (0,12~0,20 in)…
5XF-9-30-2 5/15/03 3:54 PM Page 21

INSP
ADJ
3-7
RADIATOR CAP INSPECTION
cC
9Do not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
9Do not use water containing impurities
or oil.
7. Install:
9Radiator cap
Start the engine and warm it up for a sev-
eral minutes.
8. Check:
9Coolant level
Coolant level lowAdd coolant.
EC355000
RADIATOR CAP INSPECTION
1. Inspect:
9Seal (radiator cap) 1
9Valve and valve seat 2
Crack/DamageReplace.
Exist fur deposits 3Clean or replace.
Handling notes of coolant:
The coolant is harmful so it should be handled
with special care.
w
9When coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
9When coolant splashes to your clothes.
Quickly wash it away with water and then
with soap.
9When coolant is swallowed.
Quickly make him vomit and take him to
a doctor.
5XF-9-30-3A 4/21/03 2:09 PM Page 22

INSP
ADJ
3-13
TRANSMISSION OIL REPLACEMENT
3. Check:
9Transmission oil level
EC35K002
TRANSMISSION OIL REPLACEMENT
1. Start the engine and warm it up for several
minutes and wait for five minute.
2. Place the machine on a level place and hold
it on upright position by placing the suitable
stand under the engine.
3. Place a suitable container under the engine.
Transmission oil level checking steps:
9Remove the oil check bolt 1.
9Inspect the oil level.
NOTE:
Be sure the machine is positioned straight
up when inspecting the oil level.
w
Never attempt to remove the oil check bolt
just after high speed operation. The heat-
ed oil could spout out, causing danger.
Wait until the oil cools down.
Oil flows outOil level is correct.
Oil does not flow outOil level is low.
Add transmission
oil until oil flows
out.
9Inspect the gasket (oil check bolt), replace if
damaged.
9Tighten the oil check bolt.
Recommended oil:
Yamalube 4 (10W-30) or SAE
10W-30 type SE motor oil
Oil check bolt:
10 Nm (1.0 m•kg, 7.2 ft•lb)
5XF-9-30-3A 4/21/03 2:09 PM Page 34

INSP
ADJ
3-14
PILOT AIR SCREW ADJUSTMENT
4. Remove:
9Oil drain bolt 1
9Oil filler cap 2
Drain the transmission oil.
5. Install:
9Aluminum washer
9Oil drain bolt 1
6. Fill:
9Transmission oil
Recommended oil:
Yamalube 4 (10W-30) or SAE
10W-30 type SE motor oil
Oil capacity
(periodic oil change):
0.75 L (0.66 Imp qt, 0.79 US qt)
20 Nm (2.0 m•kg, 14 ft•lb)
7. Check:
9Oil leakage
8. Check:
9Transmission oil level
9. Install:
9Oil filler cap 2
EC35L021
PILOT AIR SCREW ADJUSTMENT
1. Adjust:
9Pilot air screw 1
Adjusting steps:
9Turn in the pilot air screw until it is lightly
seated.
9Turn out the pilot air screw by the factory-set
number of turns.
NOTE:
To optimize the fuel flow at a smaller throttle
opening, each machine’s pilot air screw has
been individually set at the factory. Before
adjusting the pilot air screw, turn it in fully and
count the number of turns. Record this num-
ber as the factory-set number of turns out.
Pilot air screw:
1 turn out
*7/8 turns out
(for reference only)
*For EUROPE
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