Page 140 of 432

ELECTRICAL SYSTEM
3-40
EAS2GBB130
ELECTRICAL SYSTEM
EAS2GBB131CHECKING THE SPARK PLUG
1. Remove:
• Seat
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
• Fuel tank “1”
Refer to “FUEL TANK” on page 8-1.
ECA
NOTICE
Do not use too much force to pull the hose.
TIP
Remove the fuel tank, turn this 180 ° clockwise,
and put it in the frame “2” as shown.
2. Remove:
• Spark plug cap
• Spark plug
Refer to “CAMSHAFT” on page 6-12.
ECA
NOTICE
In order not to allow the dirt accumulated
around the spark plug to drop from the
spark plug hole into the cylinder, clean it be-
fore removing the spark plug.
3. Check:
• Spark plug type
Wrong type Replace.
4. Check:
• Electrode
Damage/wear Replace the spark plug.
• Insulator
Abnormal color Replace the spark plug.
Normal color is medium-to-light tan.
5. Clean:
• Spark plug
(with a spark plug cleaner or a wire brush)6. Measure:
• Spark plug gap “a”
Out of specification Adjust the spark plug
gap.
7. Install:
• Spark plug
TIP
Before installing the spark plug, clean the spark
plug and gasket surface.
8. Install:
• Spark plug cap
• Fuel tank
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GBB132CHECKING THE IGNITION TIMING
1. Remove:
• Timing mark accessing screw “1”
2. Attach:
• Timing light “1”
• Digital tachometer “2”
To the high tension code “3”. Manufacturer/model
NGK/LMAR8G
1
1
2
Spark plug gap
0.7–0.8 mm (0.028–0.031 in)
Spark plug
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
T R..
1
Page 141 of 432

ELECTRICAL SYSTEM
3-41
3. Adjust:
• Engine idling speed
Refer to “ADJUSTING THE ENGINE
IDLING SPEED” on page 3-18.
4. Check:
• Ignition timing
Check whether the alignment mark “a” on
the left crankcase cover is within the firing
range “b” on the rotor.
Incorrect firing range Check rotor and
Crankshaft position sensor.
5. Install:
• Timing mark accessing screw
EAS2GBB133CHECKING AND CHARGING THE BATTERY
Refer to “CHECKING AND CHARGING THE
BATTERY” on page 9-69.
EAS2GBB134REPLACING THE HEADLIGHT BULBEWA
WARNING
Since the headlight bulb gets extremely hot,
keep flammable products and your hands
away from the bulb until it has cooled down.
1. Remove:
• Headlight unit bolt “1”
TIP
After you have removed the headlight unit
bolts, lift and remove the headlight unit.
2. Remove:
• Headlight coupler “1”
• Bulb cover “2”
3. Remove:
• Headlight bulb “1” Timing light
90890-03141
Timing light
YU-03141
Digital tachometer
90890-06760
Digital tachometer
YU-39951-B
Timing mark accessing screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
2
1
3
ba
T R..
11
1
2
1
Page 232 of 432
ENGINE REMOVAL
6-3
Removing the electronic parts
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case cover
1 Rectifier/regulator 1
2ECU 1
3 Ignition coil 1
4 Neutral switch 1
5 AC magneto coupler 1 Disconnect.
6 Crankshaft position sensor coupler 1 Disconnect.
7 Coolant temperature sensor coupler 1 Disconnect.
For installation, reverse the removal proce-
dure.
T.R.
T.R.
T.R.T.R.
7 3
6
5
142
LT
New
LS
Page 330 of 432
THROTTLE BODY
8-7
EAS2GBB351
THROTTLE BODY
Removing the throttle body
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
ECU Refer to “ENGINE REMOVAL” on page 6-1.
Ignition coil Refer to “ENGINE REMOVAL” on page 6-1.
1 Intake air temperature sensor coupler 1 Disconnect.
2 Breather hose 3 1
3 Air filter case 1
4 Fuel injector coupler 1 Disconnect.
5 Intake air pressure sensor coupler 1 Disconnect.
6 Throttle position sensor coupler 1 Disconnect.
7 Throttle cable cover 1
8 Throttle cable 2
3
1
2
7
11
12
10
9
4
8
6
5
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
3.0 Nm (0.30 m kgf, 2.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
Page 335 of 432

9
ELECTRICAL SYSTEM
IGNITION SYSTEM.......................................................................................... 9-2
CIRCUIT DIAGRAM ................................................................................... 9-2
TROUBLESHOOTING ............................................................................... 9-4
ELECTRIC STARTING SYSTEM..................................................................... 9-6
CIRCUIT DIAGRAM ................................................................................... 9-6
STARTING CIRCUIT CUT-OFF SYSTEM OPERATION ........................... 9-8
TROUBLESHOOTING ............................................................................. 9-10
CHARGING SYSTEM..................................................................................... 9-12
CIRCUIT DIAGRAM ................................................................................. 9-12
TROUBLESHOOTING ............................................................................. 9-14
LIGHTING SYSTEM....................................................................................... 9-16
CIRCUIT DIAGRAM ................................................................................. 9-16
TROUBLESHOOTING ............................................................................. 9-18
SIGNALING SYSTEM.................................................................................... 9-20
CIRCUIT DIAGRAM ................................................................................. 9-20
TROUBLESHOOTING ............................................................................. 9-22
COOLING SYSTEM........................................................................................ 9-24
CIRCUIT DIAGRAM ................................................................................. 9-24
TROUBLESHOOTING ............................................................................. 9-26
FUEL INJECTION SYSTEM........................................................................... 9-28
CIRCUIT DIAGRAM ................................................................................. 9-28
ECU SELF-DIAGNOSTIC FUNCTION ..................................................... 9-30
TROUBLESHOOTING METHOD ............................................................. 9-31
YAMAHA DIAGNOSTIC TOOL ................................................................ 9-32
TROUBLESHOOTING DETAILS ............................................................. 9-35
FUEL PUMP SYSTEM.................................................................................... 9-56
CIRCUIT DIAGRAM ................................................................................. 9-56
TROUBLESHOOTING ............................................................................. 9-58
Page 336 of 432

ELECTRICAL COMPONENTS....................................................................... 9-60
CHECKING THE SWITCHES .................................................................. 9-64
CHECKING THE BULBS AND BULB SOCKETS .................................... 9-67
CHECKING THE FUSES ......................................................................... 9-68
CHECKING AND CHARGING THE BATTERY ........................................ 9-69
CHECKING THE RELAYS ....................................................................... 9-72
CHECKING THE DIODE .......................................................................... 9-73
CHECKING THE IGNITION SPARK GAP................................................ 9-73
CHECKING THE SPARK PLUG CAP ...................................................... 9-74
CHECKING THE IGNITION COIL ............................................................ 9-74
CHECKING THE CRANKSHAFT POSITION SENSOR........................... 9-75
CHECKING THE LEAN ANGLE SENSOR............................................... 9-75
CHECKING THE STARTER MOTOR OPERATION ................................ 9-76
CHECKING THE STATOR COIL ............................................................. 9-76
CHECKING THE RECTIFIER/REGULATOR ........................................... 9-76
CHECKING THE SPEED SENSOR ......................................................... 9-77
CHECKING THE FUEL SENDER ............................................................ 9-77
CHECKING THE RESISTER ................................................................... 9-78
CHECKING THE RADIATOR FAN MOTOR ............................................ 9-78
CHECKING THE COOLANT TEMPERATURE SENSOR........................ 9-78
CHECKING THE THROTTLE POSITION SENSOR ................................ 9-79
CHECKING THE THROTTLE POSITION SENSOR INPUT VOLTAGE .. 9-80
CHECKING THE INTAKE AIR PRESSURE SENSOR ............................ 9-80
CHECKING THE INTAKE AIR TEMPERATURE SENSOR ..................... 9-80
CHECKING THE FUEL INJECTOR ......................................................... 9-81
Page 338 of 432

IGNITION SYSTEM
9-2
EAS2GBB357
IGNITION SYSTEM
EAS2GBB358CIRCUIT DIAGRAM
ONOFF
ONOFF
BBB
BBB
RRR
RRR/L
Br Br Br
Br Br
(Gy)
(Gy)B/LGyWW WB Gy
B R
WW W
BR
R,R/Y
G
R
Y/B
R,R/W
Br
RL/R
(B)R/YR/WBr/WL/G
Br/W,BrL/W
(B) (B)Br BrL/Y Y/R
G/YBrBB
BrBrL/YY/W
(B)(B)BB GG/Y
RR/L
R Lg
W/B
(B) BGyBr RW/BB/LLYP
G/WB/Y
R/BLgG/YW
Br/W
OL/RY/BB/OL/BSbY/R L/Y P/L
Y/G
(Gy)R/L R/BR/LB/Y
R/WR/L
R/W,BrP/L
R/L R/L
(B)
(B)
(B)
(L)
(L)(B) BR/LLBR/L R/L R/L R/L R/L B/L B/L B/L B/L B/L B/L B/LL L L LBBBB
Br Br Br Br
B/LBr/W
B/LG/WLYB/L
B/LPLB/LY/GL
(B)
(B)B/OBB BSbW/B
Sb
SbG/B
L/G,L/WL/BBrG/BG/BB
BB
(B)
(B)L/BBB B
Br Br
Br BrBr
BB LY
(B)
(B)
(B)
(B)
(B)
GB
Ch Dg
Y B
BRW
Br R
B W
B/WR W
Ch DgYBBrR/WBW
R O
OR/L
B
B
BBBBBB
RRRRRR/L
BrBrBrBrBr
Br
Br
BrBrBrBrR/LR/LR/LR/LR/L
B
LLLP
PL
Y
Y
RR
Br
R/LR/L
R/L
P/L
P/L
R/L
R/L
R/LR/B
R/B
L/RL/Y
L/Y
Y/R
Y/R
G/Y
G/YG/Y
G/Y
B/Y
B/Y
R/LB/LB/L
B/LB/LB/LY/G
Y/GB/L
B/OL/BY/BW/B
W/B
G/B
L/B
W/BW/B
L/BL/BL/GL/W
L/W
L/R
Br/W
Br/W
R/W
R/W
R/Y
R/Y
G/BG/B
G/B
B/O
B/LB/LB/LB/LB/LB/LB/L
G/W
G/W
Br/W
Br/W
R/WR/WBr
O
O
OR
RGy
LLLLBBBB
B
B
B
B
BBB
B
B
RRWW
Y
Y
Dg
Dg
Ch
Ch
RW
BrBrBrBr
Br
B
W
Sb
SbSb
SbBr
Br
B
Br
Lg
Lg
R/L
R
R
RR
Gy
BB
WWWWWW
R
RRGGBB
B
Y/B
RB
BB
B
B
Br
Br
Br
B
L/G
B/L
B/WB/W
B
Page 339 of 432
IGNITION SYSTEM
9-3
1. Joint connector
2. Joint connector
4. AC magneto
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
23.Ignition coil
24.Spark plug
30.Joint connector
35.Lean angle sensor
36.Engine stop switch
48.Frame ground
49.Ignition coil sub-lead