2010 YAMAHA WR 450F Owners Manual

Page 217 of 230

YAMAHA WR 450F 2010  Owners Manual 7-9
ELECTRIC STARTING SYSTEM
REMOVING THE STARTER MOTOR
Order Part name Qty Remarks
Exhaust pipeRefer to "REMOVING THE EXHAUST PIPE 
AND SILENCER" section in the CHAPTER 3.
1 Starter motor 1

Page 218 of 230

YAMAHA WR 450F 2010  Owners Manual 7-10
ELECTRIC STARTING SYSTEM
DISASSEMBLING THE STARTER MOTOR
Order Part name Qty Remarks
1 Starter motor front cover 1
2 Washer (starter motor front cover) 1
3 Washer 1
4 Circlip 1
5O-ring 1
6 Start

Page 219 of 230

YAMAHA WR 450F 2010  Owners Manual 7-11
ELECTRIC STARTING SYSTEM
CHECKING AND REPAIRING THE 
STARTER MOTOR
1. Check:
• Commutator
Dirt→Clean with 600 grit sandpa-
per.
2. Measure:
• Commutator diameter "a"
Out of specification→

Page 220 of 230

YAMAHA WR 450F 2010  Owners Manual 7-12
ELECTRIC STARTING SYSTEM
4. Install:
• O-ring "1" 
• Circlip
• Plain washer "2"
• Washer (starter motor front cover) 
"3"
• Starter motor front cover "4"
• For installation, align the

Page 221 of 230

YAMAHA WR 450F 2010  Owners Manual 7-13
CHARGING SYSTEM
CHARGING SYSTEM
INSPECTION STEPS
If the battery is not charged, use the following inspection steps.
*1 marked: Refer to "CHECKING THE FUSE" section in the CHAPTER 3.
*2 marked: Re

Page 222 of 230

YAMAHA WR 450F 2010  Owners Manual 7-14
CHARGING SYSTEM
CHECKING THE COUPLERS AND 
LEADS CONNECTION
1. Check:
• Couplers and leads connection
Rust/dust/looseness/short-circuit
→Repair or replace.
CHECKING THE CHARGING 
VOLTAGE
1. S

Page 223 of 230

YAMAHA WR 450F 2010  Owners Manual 7-15
THROTTLE POSITION SENSOR SYSTEM
THROTTLE POSITION SENSOR SYSTEM
INSPECTION STEPS
If the throttle position sensor will not operate, use the following inspection steps.
Use the following special to

Page 224 of 230

YAMAHA WR 450F 2010  Owners Manual 7-16
THROTTLE POSITION SENSOR SYSTEM
HANDLING NOTE
Do not loosen the screw (throttle 
position sensor) "1" except when 
changing the throttle position sen-
sor due to failure because it will 
cause a