YAMAHA WR 450F 2016 Owners Manual

9-1
EAS2GC1357
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, serv ice engineers, etc.). Those who have little knowl-
edge and skill concerning servicing are requested not to undertake inspection, adjustment, disas-
sembly, or reassembly only by reference to this manual. It may lead to servicing trouble and
mechanical damage.

IGNITION SYSTEM
9-2
EAS2GC1358
IGNITION SYSTEM
EAS2GC1359CIRCUIT DIAGRAM
ONOFF
ONOFF
BBB
BBB
RRR
RRR/L
Br Br BrBr Br
(Gy)
(Gy)B/LGyWW W BGy
BR
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)B BGG/Y
RR/L
RLg
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/LLLLLBBBB
Br Br Br Br
B/LBr/W
B/LG/WLYB/L
B/LPLB/LY/GL
(B)
(B)B/OBBBSbW/B
Sb
SbG/B
L/G,L/WL/BBrG/BG/BB
BB
(B)
(B)L/BBBB
Br Br
Br BrBr
BB
LY
(B)
(B)
(B)
(B)
(B)
GB
ChDg YB
BRW
BrRBW
B/WRW
Ch DgYBBrR/WBW
R
O
OR/L
BB
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
OOR
OR
RGy
LLLLBBBB
B
B
B
B
BB
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
RBBB
BB
B
BBB
Br
Br
Br
L/G
B/L
B/WB/W
BB

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
50.Negative battery lead

IGNITION SYSTEM
9-4
EAS2GC1360TROUBLESHOOTING
The ignition system fails to operate (no spark or intermittent spark).
TIP
Before troubleshooting, remove the following part (s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank
5. Air filter case cover1. Check the fuse. Refer to “CHECKING THE FUSES”
on page 9-68. NG

Replace the fuse(s).
OK 
2. Check the battery. Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 9-69. NG

• Clean the battery terminals.
• Recharge or replace the battery.
OK 
3. Check the spark plug. Refer to “CHECKING THE SPARK
PLUG” on page 3-40. NG

Re-gap or replace the spark plug.
OK 
4. Check the ignition spark gap. Refer to “CHECKING THE IGNI-
TION SPARK GAP” on page 9-73. OK

The ignition system is normal.
NG 
5. Check the ignition coil. Refer to “CHECKING THE IGNI-
TION COIL” on page 9-74. NG

Replace the ignition coil.
OK 
6. Check the crankshaft position sen- sor.
Refer to “CHECKING THE CRANK-
SHAFT POSITION SENSOR” on
page 9-74. NG

Replace the stator assembly.
OK 
7. Check the engine stop switch. Refer to “CHECKING THE
SWITCHES” on page 9-64. NG

Replace the engine stop switch.
OK 

IGNITION SYSTEM
9-5
8. Check the lean angle sensor.Refer to “CHECKING THE LEAN
ANGLE SENSOR” on page 9-75. NG

Replace the lean angle sensor.
OK 
9. Check the entire ignition system’s wiring.
Refer to “CIRCUIT DIAGRAM” on
page 9-2. NG

Properly connect or repair the ignition sys-
tem’s wiring.
OK 
Replace the ECU.

ELECTRIC STARTING SYSTEM
9-6
EAS27160
ELECTRIC STARTING SYSTEM
EAS2GC1361CIRCUIT DIAGRAM
ONOFF
ONOFF
BBB
BBB
RRR
RRR/L
Br Br Br
Br Br
(Gy)
(Gy)B/LGyWW W BGy
BR
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)B BGG/Y
RR/L
RLg
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/LLLLLBBBB
Br Br Br Br
B/LBr/W
B/LG/WLYB/L
B/LPLB/LY/GL
(B)
(B)B/OBBBSbW/B
Sb
SbG/B
L/G,L/WL/BBrG/BG/BB
BB
(B)
(B)L/BBBB
Br Br
Br BrBr
BB
LY
(B)
(B)
(B)
(B)
(B)
GB
ChDg YB
BRW
BrRBW
B/WRW
Ch DgYBBrR/WBW
R
O
OR/L
BB
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
RGy
LLLLBBBB
B
B
B
B
BB
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
R
BB
Br
Br
Br
L/G
B/L
B/WB/W
OR
OR
BBB
B
BBBBB

ELECTRIC STARTING SYSTEM
9-7
1. Joint connector
2. Joint connector
3. Joint connector
7. Main relay
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
13.Starter motor
14.Starter relay diode
22.ECU (engine control unit)
30.Joint connector
36.Engine stop switch
37.Neutral switch
38.Diode
39.Starting circuit cut-off relay
40.Clutch switch
41.Start switch
48.Frame ground
50.Negative battery lead

ELECTRIC STARTING SYSTEM
9-8
EAS2GC1362STARTING CIRCUIT CUT-OFF SYSTEM OPERATION
If the meter light comes on, the starter motor can only operate if at least one of the following condi-
tions is met:
• The transmission is in neutral (the neutral switch is closed).
• The clutch lever is pulled to the handlebar (the clutch switch is closed).
The starting circuit cut-off relay prevents the starter motor from operating when neither of these con-
ditions has been met. In this instance, the starting ci rcuit cut-off relay is open so current cannot reach
the starter motor. When at least one of the above conditions has been met the starting circuit cut-off
relay is closed and the engine can be started by pressing the start switch.

ELECTRIC STARTING SYSTEM
9-9
a. WHEN THE TRANSMISSION IS IN NEU-TRAL
b. WHEN THE CLUTCH LEVER IS PULLED TO THE HANDLEBAR
1. Battery
2. Main fuse
3. Main relay
4. Starting circuit cut-off relay
5. Start switch
6. Diode
7. Clutch switch
8. Neutral switch
9. Starter relay
10.Starter motor

ELECTRIC STARTING SYSTEM
9-10
EAS2GC1363TROUBLESHOOTING
The starter motor fails to turn.
TIP
Before troubleshooting, remove the following part (s):
1. Seat
2. Side cover (left/right)
3. Air scoop (left/right)
4. Fuel tank
5. Air filter case cover1. Check the fuse. Refer to “CHECKING THE FUSES”
on page 9-68. NG

Replace the fuse(s).
OK 
2. Check the battery. Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 9-69. NG

• Clean the battery terminals.
• Recharge or replace the battery.
OK 
3. Check the starter motor operation. Refer to “CHECKING THE START-
ER MOTOR OPERATION” on page
9-75. OK

Starter motor is OK. Perform the electric
starting system troubleshooting, starting
with step 5.
NG 
4. Check the starter motor. Refer to “CHECKING THE START-
ER MOTOR” on page 6-38. NG

Repair or replace the starter motor.
OK 
5. Check the relay unit (Starting circuit cut-off relay).
Refer to “CHECKING THE RE-
LAYS” on page 9-72. NG

Replace the relay unit.
OK 
6. Check the diode. Refer to “CHECKING THE DIODE”
on page 9-73. NG

Replace the diode.
OK 
7. Check the starter relay. Refer to “CHECKING THE RE-
LAYS” on page 9-72. NG

Replace the starter relay.
OK 