1-18
STARTING AND BREAK-IN
STARTING AND BREAK-IN
FUEL
Always use the recommended fuel as
stated below. Also, be sure to use
new gasoline.
Use only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to the engine inter-
nal parts such as valves, piston
rings, and exhaust system, etc.
If knocking or pinging occurs, use a
different brand of gasoline or higher
octane grade.
• For refueling, be sure to stop the
engine and use enough care not
to spill any fuel. Also be sure to
avoid refueling close to a fire.
• Refuel after the engine, exhaust
pipe, etc. have cooled off.
Gasohol (For Canada)
There are two types of gasohol: gas-
ohol containing ethanol and that con-
taining methanol. Gasohol containing
ethanol can be used if the ethanol
content does not exceed 10%. Gaso-
hol containing methanol is not recom-
mended by Yamaha because it can
cause damage to the fuel system or
vehicle performance problems.
HANDLING NOTE
Never start or run the engine in a
closed area. The exhaust fumes
are poisonous; they can cause
loss of consciousness and death
in a very short time. Always oper-
ate the machine in a well-ventilated
area.
• The carburetor on this machine
has a built-in accelerator pump.
Therefore, when starting the en-
gine, do not operate the throttle
or the spark plug will foul.
• Unlike a two-stroke engine, this
engine cannot be kick started
when the throttle is open be-
cause the kickstarter may kick
back. Also, if the throttle is open
the air/fuel mixture may be too
lean for the engine to start.
• Before starting the machine, per-
form the checks in the pre-opera-
tion check list.
AIR FILTER MAINTENANCE
According to "CLEANING THE AIR
FILTER ELEMENT" section in the
CHAPTER 3, apply the foam-air-filter
oil or its equivalent to the element.
(Excess oil in the element may ad-
versely affect engine starting.)
STARTING A COLD ENGINE
This model is equipped with an igni-
tion circuit cut-off system. The engine
can be started under the following
conditions.
• When the transmission is in neutral.
• When the clutch is disengaged with
the transmission in any position.
However, it is recommended to shift
into neutral before starting the en-
gine.
1. Inspect the coolant level.
2. Turn the fuel cock to "ON".
3. Push on the main switch to "ON".
4. Shift the transmission into neutral.
5. Fully open the cold starter knob
"1".
6. Start the engine by pushing the
start switch or by kicking the kick-
starter crank.
If the engine fails to start by pushing
the start switch, release the switch,
wait a few seconds, and then try
again. Each starting attempt should
be as short as possible to preserve
the battery. Do not crank the engine
more than 10 seconds on any one at-
tempt. If the engine does not start
with the starter motor, try using the
kickstarter crank.
• If the starter motor will not turn
when pushing the start switch,
stop pushing it immediately and
kick start the engine in order to
avoid the load on the motor.
• Do not open the throttle while
kicking the kickstarter crank.
Otherwise, the kickstarter crank
may kick back.
7. Return the cold starter knob to its
original position and run the en-
gine at 3,000–5,000 r/min for 1 or
2 minutes.
Since this model is equipped with an
accelerator pump, if the engine is
raced (the throttle opened and
closed), the air/fuel mixture will be too
rich and the engine may stall. Also
unlike a two-stroke engine, this model
can idle.
Do not warm up the engine for ex-
tended periods of time.
STARTING A WARM ENGINE
Do not operate the cold starter knob
and throttle. Pull the hot starter lever
"1" and start the engine by pushing
the start switch or by kicking the kick-
starter crank forcefully with a firm
stroke. As soon as the engine starts,
Release the hot starter lever to close
the air passage. Recommended fuel:
Premium unleaded
gasoline only with a re-
search octane number
of 95 or higher.
1-20
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Concerning the tightening torque, refer to "TIGHTENING TORQUES" section in the CHAPTER 2.
Frame construction Frame to rear frame
Combined seat and fuel tank Fuel tank to frame
Exhaust system Silencer to rear frame
Engine mounting Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering Steering stem to handlebar Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Suspension Front Steering stem to front fork Front fork to upper bracket
Front fork to lower bracket
Rear For link type Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Installation of rear shock absorber Rear shock absorber to frame
Installation of swingarm Tightening of pivot shaft
Wheel Installation of wheel Front Tightening of wheel axle
Tightening of axle holder
Rear Tightening of wheel axle
Wheel to rear wheel sprocket
Brake Front Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handlebar
Tightening of bleed screw
Tightening of brake hose holder
Rear Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Tightening of brake hose holder
Fuel system Fuel tank to fuel cock
Lubrication system Tightening of oil hose clamp
2-1
GENERAL SPECIFICATIONS
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model name: WR250FB (USA, CDN, AUS, NZ)
WR250F (EUROPE, ZA)
Model code number: 1HC5 (USA)
1HC6 (CDN)
1HC7 (EUROPE)
1HC8 (AUS, NZ, ZA)
Dimensions: USA, CDN, ZA AUS, NZ EUROPE
Overall length 2,165 mm (85.24
in)2,175 mm (85.63
in)2,185 mm (86.02
in)
Overall width 825 mm (32.48 in)←←
Overall height 1,300 mm (51.18
in)1,305 mm (51.38
in)←
Seat height 980 mm (38.58 in) 990 mm (38.98 in)←
Wheelbase 1,480 mm (58.27
in)←1,485 mm (58.46
in)
Minimum ground clearance 365 mm (14.37 in)←←
Weight:
USA CDN, AUS, NZ,
ZAEUROPE
Curb weight
115 kg (254 lb)116 kg (256 lb) 117 kg (258 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder
Displacement 250 cm
3 (8.80 Imp oz, 8.45 US oz)
Bore × stroke 77.0 × 53.6 mm (3.03 × 2.11 in)
Compression ratio 12.5 : 1
Starting system Kick and electric starter
Lubrication system: Dry sump
Oil type or grade:
Engine oil Recommended brand: YAMALUBE
SAE 10W-30, SAE 10W-40, SAE 10W-50,
SAE 15W-40, SAE 20W-40 or SAE 20W-50
API service SG type or higher,
JASO standard MA
Oil capacity:
Engine oil
Periodic oil change 1.1 L (0.97 Imp qt, 1.16 US qt)
With oil filter replacement 1.2 L (1.06 Imp qt, 1.27 US qt)
Total amount 1.4 L (1.23 Imp qt, 1.48 US qt)
Coolant capacity (including all routes): 0.99 L (0.87 Imp qt, 1.05 US qt)
Air filter: Wet type element
2-3
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINEShock 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 310 mm (12.2 in)
Electrical:
Ignition system CDI
Generator system AC magneto
Battery type YTZ7S (F)
Battery voltage/capacity 12V/6 AH
Specific gravity 1.310
Headlight type: Quartz bulb (halogen)
Bulb wattage × quantity:
Headlight 12 V 35/36.5 W × 1
Taillight 12 V 1.6/0.3 W × 1
Item Standard Limit
Cylinder head:
Warp limit ---- 0.05 mm (0.002
in)
Cylinder:
Bore size 77.00–77.01 mm (3.0315–3.0319 in) ----
Out of round limit ---- 0.05 mm (0.002
in)
Camshaft:
Drive method Chain drive (Left) ----
Camshaft cap inside diameter 22.000–22.021 mm (0.8661–0.8670 in) ----
Camshaft outside diameter 21.959–21.972 mm (0.8645–0.8650 in) ----
Shaft-to-cap clearance 0.028–0.062 mm (0.0011–0.0024 in) 0.08 mm (0.003
in)
Cam dimensions
2-7
MAINTENANCE SPECIFICATIONS
Oil ring:
Dimensions (B × T) 1.50 × 2.25 mm (0.06 × 0.09 in) ----
End gap (installed) 0.10–0.40 mm (0.004–0.016 in) ----
Crankshaft:
Crank width "A" 55.95–56.00 mm (2.203–2.205 in) ----
Runout limit "C" 0.03 mm (0.0012 in) 0.05 mm (0.002
in)
Big end side clearance "D" 0.15–0.45 mm (0.0059–0.0177 in) 0.50 mm (0.02
in)
Small end free play "F" 0.4–1.0 mm (0.02–0.04 in) 2.0 mm (0.08
in)
Clutch:
Friction plate thickness 2.9–3.1 mm (0.114–0.122 in) 2.7 mm (0.106
in)
Quantity 9 ----
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 37.0 mm (1.46 in) 36.0 mm (1.42
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 ----Item Standard Limit
2-8
MAINTENANCE SPECIFICATIONS
CHASSISCarburetor: USA, CDN, ZA,
AUS, NZEUROPE
Type/manufacturer FCR-MX37/KEIHIN←----
I. D. mark 5UME E0 5UML L0 ----
Main jet (M.J) #170 #160 ----
Main air jet (M.A.J) #115←----
Jet needle (J.N) NJRU NNGU ----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #42 #45 ----
Pilot air jet (P.A.J) #70←----
Pilot outlet (P.O) ø0.9←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #68←----
Leak jet (Acc.P) #70←----
Float height (F.H) 8 mm (0.31 in)←----
Engine idle speed 1,750–1,950 r/min←----
Intake vacuum 31.3–36.7 kPa
(235–275 mmHg,
9.25–10.83 inHg)←----
Hot starter lever free play 3–6 mm (0.12–0.24
in)←----
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.09–0.17 mm (0.0035–0.0067 in) 0.24 mm (0.009
in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 in)
Cooling:
Radiator core size
Width 120.2 mm (4.73 in) ----
Height 240 mm (9.45 in) ----
Thickness 22 mm (0.87 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.54 L (0.48 Imp qt, 0.57 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
Item Standard Limit
Steering system:
Steering bearing typeTaper roller bearing ----
2-9
MAINTENANCE SPECIFICATIONS
Front suspension:
Front fork travel 300 mm (11.8 in) ----
Fork spring free length 460 mm (18.1 in) 455 mm (17.9
in)
Spring rate, STD K = 4.4 N/mm (0.449 kg/mm, 25.1 lb/in) ----
Optional spring/spacer Yes ----
Oil capacity 648 cm
3 (22.8 lmp oz, 21.9 US oz) ----
Oil level 132 mm (5.20 in) ----
tube and damper rod fully compressed without
spring.)95–150 mm (3.74–5.91 in) ----
Oil grade Suspension oil "S1" ----
Inner tube outer diameter 48 mm (1.89 in) ----
Front fork top end 5 mm (0.20 in) ----
Rear suspension: USA, CDN AUS, NZ, ZA EUROPE
Shock absorber travel 130 mm (5.12
in)←←----
Spring free length 260 mm (10.24
in)←←----
Fitting length 249 mm (9.80
in)245.0 mm (9.65
in)248.5 mm (9.78
in)----
Preload length
(0.06–0.87 in)←←----
Spring rate, STD K = 52.0 N/mm
(5.30 kg/mm,
296.8 lb/in)←←----
Optional spring Yes←←----
Enclosed gas pressure 1,000 kPa (10
kg/cm
2, 142
psi)←←----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04
in)
Wheel: USA, CDN, ZA AUS, NZ, EUROPE
Front wheel type Spoke wheel←----
Rear wheel type Spoke wheel←----
Front rim size/material 21 × 1.60/Aluminum←----
Rear rim size/material 18 × 1.85/Aluminum18 × 2.15/Aluminum ----
Rim runout limit:
Radial ---- ---- 2.0 mm (0.08
in)
Lateral ---- ---- 2.0 mm (0.08
in) Item Standard Limit
2-10
MAINTENANCE SPECIFICATIONS
ELECTRICALDrive chain:
Type/manufacturer DID520VM/DAIDO ----
Number of links 113 links + joint ----
Chain slack 48–58 mm (1.9–2.3 in) ----
Chain length (15 links) ---- 239.3 mm
(9.42 in)
Front disc brake:
Disc outside dia.×Thickness 250 × 3.0 mm (9.84 × 0.12 in) 250 × 2.5 mm
(9.84 × 0.10 in)
Pad thickness 4.4 mm (0.17 in) 1.0 mm (0.04
in)
Master cylinder inside dia. 11.0 mm (0.433 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) × 2 ----
Brake fluid type DOT #4 ----
Rear disc brake:
Disc outside dia.×Thickness 245 × 4.0 mm (9.65 × 0.16 in) 245 × 3.5 mm
(9.65 × 0.14 in)
Deflection limit ---- 0.15 mm
(0.006 in)
Pad thickness 6.4 mm (0.25 in) 1.0 mm (0.04
in)
Master cylinder inside dia. 11.0 mm (0.433 in) ----
Caliper cylinder inside dia. 25.4 mm (1.000 in) × 1 ----
Brake fluid type DOT #4 ----
Brake lever and brake pedal:
Brake lever position 95 mm (3.74 in) ----
Brake pedal height (vertical height above footrest
top)10 mm (0.39 in) ----
Clutch lever free play (lever end) 8–13 mm (0.31–0.51 in) ----
Throttle grip free play3–5 mm (0.12–0.20 in) ---- Item Standard Limit
Item Standard Limit
Ignition system:
Advancer type Electrical ----
CDI: USA, CDN AUS, NZ, ZA EUROPE
Pickup coil resistance (color) 248–372 Ωat
20 °C (68 °F)
(White–Red)←←----
CDI unit-model/manufacturer 5UM-E0/YA-
MAHA5UM-F1/YA-
MAHA5UM-L1/YA-
MAHA----
Ignition coil:
Model/manufacturer 5UL-10/DENSO ----
Minimum spark gap 6 mm (0.24 in) ----
Primary coil resistance 0.08–0.10 Ωat 20 °C (68 °F) ----
Secondary coil resistance 4.6–6.8 kΩat 20 °C (68 °F) ----