TROUBLESHOOTING
9-1
EAM20148
TROUBLESHOOTING
EAM30309
GENERAL INFORMATION
TIP
Troubleshooting information provided here does not cover all the trouble symptoms, possible causes,
and remedial actions. Some items may not apply depending on the model. Use this information as a
guide and quick reference matrix when performing basic troubleshooting. Refer to the each chapter for
detailed information on checking, adjustment, and replacement.
EAM30509
TROUBLESHOOTING OF ENGINE (fault code not detected)
TIP
If a fault code is detected, refer to the “FUEL INJECTION SYSTEM” on page 8-15.
Engine does not crank.
Engine will not start or is difficult to start, but it cranks.
Symptom
Possible cause
Actions
Starter motor does not operate
Refer to “TROUBLESHOOTING” under “ELECTRIC STARTING
Starter motor operates, but the
engine does not crank.
Starter clutch malfunction
Replace the starter clutch.
Improper oil grade (starter clutch
slipping)
Change to recommended engine
oil.
Stuck piston or seized crankshaft
Disassemble and check the
engine. Replace defective parts.
Symptom
Possible cause
Actions
Spark plug does not produce a
spark
Refer to “TROUBLESHOOTING” under “IGNITION SYSTEM” on page
Fuel not supplied
—
Measure the fuel pressure.
Empty fuel tank
Fill the fuel tank with fuel.
Clogged fuel tank cap breather
hole
Clean the fuel tank cap.
Clogged or damaged fuel hose
Clean, repair, or replace the fuel
hose.
Fuel leakage
Check the fuel passage. Repair or
replace as necessary.
Clogged fuel pump
Clean or replace the fuel pump.
Cracks or damage in fuel pump
Replace the fuel pump.
Fuel pump malfunction
Refer to “TROUBLESHOOTING”
Failed or clogged fuel injector
Replace the fuel injector.
ECU failure
Replace the ECU.
Summary of Contents for YZ450FP 2023
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 44: ...MOTORCYCLE CARE AND STORAGE 1 32...
Page 61: ...TIGHTENING TORQUES 2 16...
Page 72: ...CABLE ROUTING DIAGRAM 2 27 Frame and battery top view 2 1 B 5 4 3 A 7 4 E 6 D 2 3 C...
Page 76: ...CABLE ROUTING DIAGRAM 2 31...
Page 154: ...REAR BRAKE 4 38 system Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM on page 3 26...
Page 194: ...CHAIN DRIVE 4 78...
Page 278: ...TRANSMISSION 5 82...
Page 300: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM...
Page 305: ...IGNITION SYSTEM 8 6...
Page 306: ...ELECTRIC STARTING SYSTEM 8 7 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM...
Page 310: ...CHARGING SYSTEM 8 11 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM...
Page 313: ...CHARGING SYSTEM 8 14...
Page 314: ...FUEL INJECTION SYSTEM 8 15 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM B...
Page 339: ...FUEL INJECTION SYSTEM 8 40...
Page 340: ...FUEL PUMP SYSTEM 8 41 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM...
Page 356: ...ELECTRICAL COMPONENTS 8 57...
Page 372: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15...
Page 382: ...CHASSIS 10 9...
Page 384: ......
Page 386: ......
Page 387: ...B YZ450FP 2023 WIRING DIAGRAM BHR 2819U 10_W D indd 1 2022 08 09 13 16 06...