Yamaha WR450F(Y) 2009 Owner's Service Manual page 210

INSPECTION STEPS
If the starter motor will not operate, use the following inspection steps.
*1 Check fuse.
OK ↓
*2 Check battery.
OK ↓
Check each coupler and wire connection.
OK ↓
*3 Check main switch.
OK ↓
Check starter motor operation.
OK ↓
Check starting circuit cut-off relay.
OK ↓
Check starter relay.
OK ↓
*4 Check neutral switch.
OK ↓
Check clutch switch.
OK ↓
Check diode.
OK ↓
Check start switch.
*1 marked: Refer to "CHECKING THE FUSE" section in the CHAPTER 3.
*2 marked: Refer to "CHECKING AND CHARGING THE BATTERY" section in the CHAPTER 3.
*3 marked: Refer to "CHECKING THE MAIN SWITCH" section.
*4 marked: Refer to "CHECKING THE NEUTRAL SWITCH" section.
• Remove the following parts before inspection.
1. Seat
2. Rear fender
• Use 12 V battery in this inspection.
• Use the following special tools in this inspection.
Pocket tester:
YU-3112-C/90890-03112
ELECTRIC STARTING SYSTEM
No good → Replace fuse and check wire harness.
No good → Recharge or replace.
No good → Repair or replace.
No good → Replace.
No good → Repair or replace.
No good → Replace.
No good → Replace.
No good → Replace.
No good → Replace.
No good → Replace.
No good → Replace.
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