TROUBLESHOOTING
9-2
Incorrect idling speed or mid-to-high speed
—
Water or foreign material in fuel,
degraded fuel
Change fuel.
Loose spark plug
Tighten the spark plug to the spec-
ified torque.
Loose cylinder head or cylinder
Tighten bolts or nuts on cylinder
head and cylinder to the specified
torque.
Damaged cylinder head gasket
Replace the cylinder head gasket.
Incorrect valve timing
Adjust the valve timing.
Incorrect valve clearance
Adjust the valve clearance.
Worn valve guide
Replace the valve guide.
Bent, damaged, or stuck valve
Replace the valve.
Poor contact between valve and
valve seat
Reface the valve-to-valve-seat
contact.
Fatigued or broken valve spring
Replace the valve spring.
Worn, damaged, or stuck piston
ring
Replace the piston and piston
rings as a set.
Seized or damaged piston
Replace the piston and piston
rings as a set.
Worn or damaged cylinder bore
Replace the cylinder, piston, and
piston rings as a set.
Symptom
Possible cause
Actions
Spark plug does not produce a
spark
Incorrect spark plug gap
Adjust the spark plug gap.
Worn or damaged spark plug
Replace the spark plug.
Defective spark plug cap
Replace the spark plug cap.
Defective ignition coil
Replace the ignition coil.
ECU failure
Replace the ECU.
Low fuel pressure
—
Measure the fuel pressure.
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”
Fuel not supplied
Failed or clogged fuel injector
Replace the fuel injector.
ECU failure
Replace the ECU.
Symptom
Possible cause
Actions
Summary of Contents for WR250FM 2021
Page 5: ...EAM20093 YAMAHA MOTOR CORPORATION U S A WR MOTORCYCLE LIMITED WARRANTY...
Page 8: ......
Page 10: ......
Page 52: ...MOTORCYCLE CARE AND STORAGE 1 40...
Page 62: ...ELECTRICAL SPECIFICATIONS 2 9 Radiator fan motor fuse 5 0 A Spare fuse 15 0 A...
Page 70: ...CABLE ROUTING DIAGRAM 2 17 EAM20152 CABLE ROUTING DIAGRAM Frame and engine left side view...
Page 72: ...CABLE ROUTING DIAGRAM 2 19 Frame and engine right side view...
Page 74: ...CABLE ROUTING DIAGRAM 2 21 Handlebar front view...
Page 76: ...CABLE ROUTING DIAGRAM 2 23 Frame and engine top view...
Page 78: ...CABLE ROUTING DIAGRAM 2 25 Frame and battery top view...
Page 80: ...CABLE ROUTING DIAGRAM 2 27 Rear brake right side view...
Page 82: ...CABLE ROUTING DIAGRAM 2 29 Front brake front view and right side view...
Page 84: ...CABLE ROUTING DIAGRAM 2 31 Taillight top view and right side view...
Page 86: ...CABLE ROUTING DIAGRAM 2 33...
Page 203: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Oil filter element 2 Oil pump...
Page 204: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 4 1 Intake camshaft 2 Exhaust camshaft...
Page 278: ...TRANSMISSION 5 78...
Page 288: ...WATER PUMP 6 9...
Page 298: ...THROTTLE BODY 7 9...
Page 301: ......
Page 302: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM...
Page 306: ...ELECTRIC STARTING SYSTEM 8 5 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM...
Page 312: ...CHARGING SYSTEM 8 11 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM...
Page 315: ...CHARGING SYSTEM 8 14...
Page 316: ...SIGNALING SYSTEM 8 15 EAM20154 SIGNALING SYSTEM EAM30348 CIRCUIT DIAGRAM...
Page 320: ...LIGHTING SYSTEM 8 19 EAM20153 LIGHTING SYSTEM EAM30346 CIRCUIT DIAGRAM...
Page 323: ...LIGHTING SYSTEM 8 22...
Page 324: ...COOLING SYSTEM 8 23 EAM20155 COOLING SYSTEM EAM30350 CIRCUIT DIAGRAM...
Page 327: ...COOLING SYSTEM 8 26...
Page 328: ...FUEL INJECTION SYSTEM 8 27 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM...
Page 353: ...FUEL INJECTION SYSTEM 8 52...
Page 354: ...FUEL PUMP SYSTEM 8 53 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM...
Page 388: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15...
Page 398: ...CHASSIS 10 9...
Page 400: ......
Page 402: ......
Page 403: ...WR250FM 2021 WIRING DIAGRAM BAK 2819U 11_W D indd 1 2020 07 01 12 01 28...
Page 404: ...WR250FM 2021 WIRING DIAGRAM BAK 2819U 11_W D indd 2 2020 07 01 12 01 28...