2003 YAMAHA WR 250F ignition

CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM............. 6-1
MAP-CONTROLLED CDI UNIT.. 6-3
IGNITION SYSTEM..................... 6-8
ELECTRIC STARTING
SYSTEM.................................... 6-21
CHARGING SYSTEM............... 6-45
THROTTLE POSITION
SENSOR SYSTEM.................... 6-53
LIGHTING SYSTEM.................. 6-67
CHAPTER 7
TUNING
ENGINE....................................... 7-1
CHASSIS................................... 7-23
CHAPITRE 6
PARTIE
ELECTRIQUE
COMPOSANTS ELECTRIQUES
ET SCHEMA DE CABLAGE........ 6-2
BLOC CDI CONTROLE PAR
MICROPROCESSEUR.................. 6-4
SYSTEME D’ALLUMAGE............ 6-9
SYSTEM DE DEMARRAGE
ELECTRIQUE............................... 6-21
SYSTEME DE RECHARGE........ 6-46
CIRCUIT DU CAPTEUR DE
PAPILLON DES GAZ.................. 6-54
SYSTEME D’ECLAIRAGE......... 6-68
CHAPITRE 7
MISES AU POINT
MOTEUR......................................... 7-1
PARTIE CYCLE........................... 7-23

1 - 12
GEN
INFO
SPECIAL TOOLS
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.
YU-8036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.
YM-4019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.
YM-4111, 90890-04111
YM-4116, 90890-04116Valve guide remover
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
This tool is needed to remove and install the valve
guide.
YM-4112, 90890-04112
YM-4117, 90890-04117Valve guide installer
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
This tool is needed to install the valve guide.
YM-4113, 90890-04113
YM-4118, 90890-04118Valve guide reamer
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
This tool is needed to rebore the new valve guide.
YM-04141, 90890-04141 Rotor puller
This tool is used to remove the flywheel magneto.
Part number Tool name/How to use Illustration

1 - 13
GEN
INFO
SPECIAL TOOLS
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.
ACC-QUICK-GS-KT
90890-85505Quick gasket
®
YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.
Part number Tool name/How to use Illustration

GENERAL SPECIFICATIONS
2 - 3
SPEC
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
Generator system AC magneto
Battery type YTX5L-BS
Battery voltage/capacity 12 V/4 AH
Specific gravity 1.320
Headlight type: Quartz bulb (halogen)
Bulb wattage × quantity:
Headlight 12 V 60/55 W × 1
Taillight 12 V 21/5 W × 1

MAINTENANCE SPECIFICATIONS
2 - 17
SPEC
EC212300
ELECTRICAL
Item Standard Limit
Ignition system:
Advancer type Electrical ----
CDI:
Pickup coil resistance (color) 248 ~ 372 Ω at 20°C (68 °F)
(White – Red)----
CDI unit-model/manufacturer 5UM-00/YAMAHA (For USA) ----
5UM-10/YAMAHA (Except for USA) ----
Ignition coil:
Model/manufacturer 5UL-00/DENSO ----
Minimum spark gap 6 mm (0.24 in) ----
Primary coil resistance 0.08 ~ 0.10 Ω at 20 °C (68 °F) ----
Secondary coil resistance 4.6 ~ 6.8 kΩ at 20 °C (68 °F) ----
Charging system:
System type AC magneto ----
Model/manufacturer 5UM-00/YAMAHA ----
Normal output 14 V/120 W at 5,000 r/min ----
Charging coil resistance (color) 0.288 ~ 0.432 Ω at 20 °C (68 °F)
(White – Ground)----
Lighting coil resistance (color) 0.224 ~ 0.336 Ω at 20 °C (68 °F)
(Yellow – Ground)----
Rectifier/regulator:
Regulator type Semiconductor short circuit ----
Model/manufacture SH712AA/SHINDENGEN ----
Regulated voltage (AC) 13.0 ~ 14.0 V ----
Regulated voltage (DC) 14.1 ~ 14.9 V ----
Rectifier capacity (AC) 12 A ----
Rectifier capacity (DC) 8 A ----
Electric starting system:
Type Constant mesh ----
Starter motor:
Model/manufacturer 5UM00/YAMAHA ----
Operation voltage 12 V ----
Output 0.35 kW ----
Armature coil resistance 0.0189 ~ 0.0231 Ω at 20 °C (68 °F) ----
Brush overall length 7 mm (0.28 in) 3.5 mm (0.14 in)
Brush quantity 2 pcs. ----
Spring force 3.92 ~ 5.88 N
(400 ~ 600 g, 14.1 ~ 21.2 oz)----
Commutator diameter 17.6 mm (0.69 in) 16.6 mm (0.65 in)
Mica undercut (depth) 1.5 mm (0.06 in) ----

SPEC
2 - 99
CABLE ROUTING DIAGRAM
ÊFasten the diode and rectifier/regulator lead, with the diode at
its white tape and the rectifier/regulator lead at its protecting
tube.
ËFasten the wire harness, starter motor lead and negative bat-
tery lead so that the plastic locking tie ends do not contact the
ignition coil lead.
ÌFasten the wire harness, rectifier/regulator lead, coolant reser-
voir hose, hot starter cable, negative battery lead and starter
motor lead.
ÍFasten the wire harness, negative battery lead, starter motor
lead, rectifier/regulator lead and coolant reservoir hose at the
white tape for the negative battery lead.
ÎFasten the wire harness at its white tape.ÏFasten the wire harness, throttle position sensor lead (in the
wire harness), starter motor lead and negative battery lead.
ÐMake sure that the throttle position sensor coupler does not go
outside the chassis.
ÑFasten the throttle position sensor lead.
ÒPass the carburetor breather hoses, carburetor overflow hose
and coolant reservoir breather hose between the connecting
rod and cross tube (frame).
ÓFasten the neutral switch lead and oil hose together with the
plastic locking ties and cut off the tie ends.
ÔPass the cylinder head breather hose through the hose guide.
ÕFasten the neutral switch lead.

SPEC
2 - 103
CABLE ROUTING DIAGRAM
1Hot starter cable
2Cable guide
3Throttle cable (return)
4Throttle cable (pull)
5Ignition coil
6Coolant reservoir breather hose
7Rectifier/regulator
8Coolant reservoir hose
9Rectifier/regulator lead
0Clamp
ACDI unit lead
BCDI unit
CCDI unit bandDCDI unit stay
ERectifier/regulator bracket
ÈPass the throttle cables and hot starter cable through the cable
guides.
ÉPass the throttle cables and hot starter cable between the radi-
ator and frame, then under the radiator mounting boss.
ÊPass the throttle cables on the outside of the ignition coil.
ËPass the carburetor breather hose (of the throttle cable cover)
through the hose holder.

3 - 16
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-21 ~ 29
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-35
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-39 ~ 47
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-29 ~ 31
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-31 ~ 33
Brakes Check the play of front brake and effect of front and rear brake. P.3-65 ~ 77
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-79 ~ 83
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-99 ~ 101
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-101 ~ 103
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-83 ~ 97
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or when
the front forks travel up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-7 ~ 11
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-77
Lubrication Check for smooth operation. Lubricate if necessary. P.3-105
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-45
Lead connectorsCheck that the AC magneto, CDI unit, and ignition coil are
connected tightly.P.1-9
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 42