Page 24 of 912
CHAPTER 7
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM............ 7-1
IGNITION SYSTEM.................... 7-5
ELECTRIC STARTING
SYSTEM................................... 7-19
CHARGING SYSTEM.............. 7-43
THROTTLE POSITION
SENSOR SYSTEM................... 7-51
LIGHTING SYSTEM................. 7-67
SIGNALING SYSTEM.............. 7-77
CHAPITRE 7
PARTIE
ELECTRIQUE
COMPOSANTS
ELECTRIQUES ET SCHEMA
DE CABLAGE................................. 7-2
SYSTEME D’ALLUMAGE............ 7-6
DEMARRAGE ELECTRIQUE... 7-19
SYSTEME DE CHARGE............. 7-44
SYSTEME DU CAPTEUR
DE POSITION DE PAPILLON
DES GAZ........................................ 7-52
ECLAIRAGE................................. 7-68
SYSTEME DE
SIGNALISATION......................... 7-78
Page 37 of 912

1 - 12
GEN
INFO
SPECIAL TOOLS
YS-1880-A, 90890-01701 Sheave holder
This tool is used for when loosening or tightening the
flywheel magneto securing nut.
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.
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
90890-03112
90890-04111
90890-04116
90890-04141
Page 38 of 912
1 - 13
GEN
INFO
SPECIAL TOOLS
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.
YB-35956-A, 90890-06756 Vacuum/pressure pump gauge set
This tool is used to check the air induction system.
90890-85505 YAMAHA Bond No. 1215
(ThreeBond
® No. 1215)
This sealant (Bond) is used for crankcase mating
surface, etc.
Part number Tool name/How to use Illustration
90890-06754
YB-35956-A90890-06756
Page 96 of 912
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 310 mm (12.2 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 35/36.5 W × 1
Taillight 12 V 1.6/0.3 W × 1
Page 110 of 912

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-E0/YAMAHA (For USA) ----
5UM-F0/YAMAHA (Except for USA) ----
Ignition coil:
Model/manufacturer 5UL-10/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 (stator)/manufacturer 5UM 20/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 SH770AA/SHINDENGEN ----
Regulated voltage (AC) 12.5 ~ 13.5 V ----
Regulated voltage (DC) 14.0 ~ 15.0 V ----
Rectifier capacity (AC) 12 A ----
Rectifier capacity (DC) 8 A ----
Electric starting system:
Type Constant mesh ----
Starter motor:
Model/manufacturer 5UM01/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) ----
Page 200 of 912
2 - 107
SPECCABLE ROUTING DIAGRAM
1Throttle cable (pull)
2Throttle cable (return)
3Catch tank hose
4Ignition coil
5Clamp
6Air induction hose (air cut-off valve - rear of cylinder head)
7Catch tank breather hoseÈCross the pull and push throttle cables.
ÉFasten the catch tank hose and air induction hose (air cut-off
valve - rear of cylinder head) onto the frame. Locate the clamp
end facing toward the lower side of the frame and cut off the tie
end.
ÊFasten the catch tank breather hose and carburetor breather
hoses together.
ËPass the carburetor breather hose (of the throttle cable cover)
through the hose holder.
Page 227 of 912

3 - 16
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice, 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.3-35 ~ 41
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-49
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-51 ~ 59
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-41 ~ 43
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-43 ~ 45
Brakes Check the play of front brake and effect of front and rear brake. P.3-77 ~ 89
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-91 ~ 95
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-111 ~ 113
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-113 ~ 117
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-97 ~ 109
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.3-27 ~ 31
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-89
Lubrication Check for smooth operation. Lubricate if necessary. P.3-119
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-59
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 course and
weather or by taking into account the results of test runs before
riding? Are inspection and maintenance completely done?P.4-1 ~ 40
Page 270 of 912

3 - 59
INSP
ADJ
OIL PRESSURE INSPECTION
1. Check:
Oil pressure
Checking steps:
Slightly loosen the oil pressure
check bolt
1.
Start the engine and keep it
idling until oil starts to seep from
the oil pressure check bolt. If no
oil comes out after one minute,
turn the engine off so it will not
seize.
Check oil passages and oil
pump for damage or leakage.
Start the engine after solving
the problem(s) and recheck the
oil pressure.
Tighten the oil pressure check
bolt.
T R..
Oil pressure check bolt:
10 Nm
(1.0 m kg, 7.2 ft lb)
ENGINE IDLING SPEED
ADJUSTMENT
1. Start the engine and thoroughly
warm it up.
2. Adjust:
Engine idling speed
Adjustment steps:
Turn the throttle stop screw
1
until the specified engine idling
speed.
NOTE:Using a digital engine tachometer
for idle speed adjustment, detect
the engine idling speed by bring-
ing the sensing element
c of the
engine tachometer close to the
ignition coil
2.
To increase idle speed →
Turn the throttle stop screw
1 in a.
To decrease idle speed →
Turn the throttle stop screw
1 out b.
Engine idling speed:
1,750 ~ 1,950 r/min
c2
CONTROLE DE LA PRESSION
D’HUILE
1. Contrôler:
Pression d’huile
REGLAGE DU REGIME DE
RALENTI DU MOTEUR
1. Mettre le moteur en marche et bien
le laisser chauffer.
2. Régler:
Régime de ralenti Etapes du contrôle:
Desserrer légèrement le boulon de
contrôle de la pression d’huile 1.
Lancer le moteur et le laisser tour-
ner au ralenti jusqu’à ce que l’huile
commence à suinter par le boulon
de contrôle de la pression d’huile.
Si l’huile ne s’écoule toujours pas
après une minute, couper immédia-
tement le moteur afin qu’il ne se
grippe pas.
Vérifier que les passages d’huile et
la pompe à huile ne sont pas
endommagés ou ne présentent pas
de fuites.
Après avoir résolu le(s) pro-
blème(s), démarrer le moteur et
contrôler à nouveau la pression
d’huile.
Serrer le boulon de contrôle de la
pression d’huile.
T R..
Boulon de contrôle de la
pression d’huile:
10 Nm
(1,0 m kg, 7,2 ft lb)
Étapes du réglage:
Tourner la vis de butée de papillon
des gaz 1 jusqu’à obtention de la
vitesse de ralenti spécifiée.
N.B.:
A l’aide d’un compte-tours moteur
numérique pour réglage du ralenti,
déterminer le régime de ralenti en
approchant le capteur c du compte-
tours de la bobine d’allumage 2.
Pour augmenter le régime de
ralenti → Serrer la vis de butée
de papillon des gaz 1 dans le
sens a.
Pour diminuer le régime de ralenti
→ Tourner la vis de butée de
papillon des gaz 1 dans le sens
b.
Régime de ralenti:
1.750 à 1.950 tr/min
ENGINE
MOTEUR